initialise registeredNetworkEntry in startDiscoveryAndSubscriptions (by james)

* refactor to use reflect.TypeFor

* added changelog fragment file

* update changelog

---------

Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,6 +1,6 @@
 name: 🐞 Bug report
 description: Report a bug or problem with running Prysm
-labels: ["Bug"]
+type: "Bug"
 body:
   - type: markdown
     attributes:

.github/actions/gomodtidy/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.24-alpine
+FROM golang:1.25.1-alpine
 
 COPY entrypoint.sh /entrypoint.sh
 

.github/workflows/check-specrefs.yml

@@ -0,0 +1,43 @@
+name: Check Spec References
+on: [push, pull_request]
+
+jobs:
+  check-specrefs:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Check version consistency
+      run: |
+        WORKSPACE_VERSION=$(grep 'consensus_spec_version = ' WORKSPACE | sed 's/.*"\(.*\)"/\1/')
+        ETHSPECIFY_VERSION=$(grep '^version:' specrefs/.ethspecify.yml | sed 's/version: //')
+        if [ "$WORKSPACE_VERSION" != "$ETHSPECIFY_VERSION" ]; then
+          echo "Version mismatch between WORKSPACE and ethspecify"
+          echo "  WORKSPACE: $WORKSPACE_VERSION"
+          echo "  specrefs/.ethspecify.yml: $ETHSPECIFY_VERSION"
+          exit 1
+        else
+          echo "Versions match: $WORKSPACE_VERSION"
+        fi
+
+    - name: Install ethspecify
+      run: python3 -mpip install ethspecify
+
+    - name: Update spec references
+      run: ethspecify process --path=specrefs
+
+    - name: Check for differences
+      run: |
+        if ! git diff --exit-code specrefs >/dev/null; then
+          echo "Spec references are out-of-date!"
+          echo ""
+          git --no-pager diff specrefs
+          exit 1
+        else
+          echo "Spec references are up-to-date!"
+        fi
+
+    - name: Check spec references
+      run: ethspecify check --path=specrefs

.github/workflows/fuzz.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:
-          go-version: '1.23.5'
+          go-version: '1.25.1'
       - id: list
         uses: shogo82148/actions-go-fuzz/list@v0
         with:
@@ -36,7 +36,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-go@v4
         with:
-          go-version: '1.23.5'
+          go-version: '1.25.1'
       - uses: shogo82148/actions-go-fuzz/run@v0
         with:
           packages: ${{ matrix.package }}

.github/workflows/go.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Set up Go 1.24
         uses: actions/setup-go@v4
         with:
-          go-version: '1.24.0'
+          go-version: '1.25.1'
       - name: Run Gosec Security Scanner
         run: | # https://github.com/securego/gosec/issues/469
           export PATH=$PATH:$(go env GOPATH)/bin
@@ -44,27 +44,27 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-
-      - name: Set up Go 1.24
-        uses: actions/setup-go@v4
         with:
-          go-version: '1.24.0'
-          id: go
+          fetch-depth: 0
+
+      - name: Set up Go 1.25.1
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.25.1'
 
       - name: Golangci-lint
-        uses: golangci/golangci-lint-action@v5
+        uses: golangci/golangci-lint-action@v8
         with:
-          version: v1.64.5
-          args: --config=.golangci.yml --out-${NO_FUTURE}format colored-line-number
+          version: v2.4
 
   build:
     name: Build
     runs-on: ubuntu-latest
     steps:
-      - name: Set up Go 1.x
+      - name: Set up Go 1.25.1
         uses: actions/setup-go@v4
         with:
-          go-version: '1.24.0'
+          go-version: '1.25.1'
         id: go
 
       - name: Check out code into the Go module directory

.golangci.yml

@@ -1,90 +1,41 @@
+version: "2"
 run:
-  timeout: 10m
-  go: '1.23.5'
-
-issues:
-  exclude-files:
-    - validator/web/site_data.go
-    - .*_test.go
-  exclude-dirs:
-    - proto
-    - tools/analyzers
-
+  go: 1.23.5
 linters:
-  enable-all: true
-  disable:
-    # Deprecated linters:
+  enable:
+    - errcheck
+    - ineffassign
     - govet
-
-    # Disabled for now:
-    - asasalint
-    - bodyclose
-    - containedctx
-    - contextcheck
-    - cyclop
-    - depguard
-    - dogsled
-    - dupl
-    - durationcheck
-    - errname
-    - err113
-    - exhaustive
-    - exhaustruct
-    - forbidigo
-    - forcetypeassert
-    - funlen
-    - gci
-    - gochecknoglobals
-    - gochecknoinits
-    - goconst
-    - gocritic
-    - gocyclo
-    - godot
-    - godox
-    - gofumpt
-    - gomoddirectives
-    - gosec
-    - inamedparam
-    - interfacebloat
-    - intrange
-    - ireturn
-    - lll
-    - maintidx
-    - makezero
-    - mnd
-    - musttag
-    - nakedret
-    - nestif
-    - nilnil
-    - nlreturn
-    - noctx
-    - nolintlint
-    - nonamedreturns
-    - nosprintfhostport
-    - perfsprint
-    - prealloc
-    - predeclared
-    - promlinter
-    - protogetter
-    - recvcheck
-    - revive
-    - spancheck
+  disable:
     - staticcheck
-    - stylecheck
-    - tagalign
-    - tagliatelle
-    - thelper
-    - unparam
-    - usetesting
-    - varnamelen
-    - wrapcheck
-    - wsl
+    - unused
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    paths:
+      - validator/web/site_data.go
+      - .*_test.go
+      - proto
+      - tools/analyzers
+      - third_party$
+      - builtin$
+      - examples$
 
-linters-settings:
-  gocognit:
-    # TODO: We should target for < 50
-    min-complexity: 65
-
-output:
-  print-issued-lines: true
-  sort-results: true
+formatters:
+  enable:
+    - gofmt
+    - goimports
+  exclusions:
+    generated: lax
+    paths:
+      - validator/web/site_data.go
+      - .*_test.go
+      - proto
+      - tools/analyzers
+      - third_party$
+      - builtin$
+      - examples$

CHANGELOG.md

@@ -2993,7 +2993,7 @@ There are two known issues with this release:
 
 ### Added
 
-- Web3Signer support. See the [documentation](https://docs.prylabs.network/docs/next/wallet/web3signer) for more
+- Web3Signer support. See the [documentation](https://prysm.offchainlabs.com/docs/manage-wallet/web3signer/) for more
   details.
 - Bellatrix support. See [kiln testnet instructions](https://hackmd.io/OqIoTiQvS9KOIataIFksBQ?view)
 - Weak subjectivity sync / checkpoint sync. This is an experimental feature and may have unintended side effects for

DEPENDENCIES.md

@@ -2,7 +2,7 @@
 
 Prysm is go project with many complicated dependencies, including some c++ based libraries. There
 are two parts to Prysm's dependency management. Go modules and bazel managed dependencies. Be sure 
-to read [Why Bazel?](https://github.com/OffchainLabs/documentation/issues/138) to fully
+to read [Why Bazel?](https://prysm.offchainlabs.com/docs/install-prysm/install-with-bazel/#why-bazel) to fully
 understand the reasoning behind an additional layer of build tooling via Bazel rather than a pure
 "go build" project.
 

WORKSPACE

@@ -158,15 +158,15 @@ oci_register_toolchains(
 
 http_archive(
     name = "io_bazel_rules_go",
-    integrity = "sha256-JD8o94crTb2DFiJJR8nMAGdBAW95zIENB4cbI+JnrI4=",
     patch_args = ["-p1"],
     patches = [
         # Expose internals of go_test for custom build transitions.
         "//third_party:io_bazel_rules_go_test.patch",
     ],
-    strip_prefix = "rules_go-cf3c3af34bd869b864f5f2b98e2f41c2b220d6c9",
+    sha256 = "a729c8ed2447c90fe140077689079ca0acfb7580ec41637f312d650ce9d93d96",
     urls = [
-        "https://github.com/bazel-contrib/rules_go/archive/cf3c3af34bd869b864f5f2b98e2f41c2b220d6c9.tar.gz",
+        "https://mirror.bazel.build/github.com/bazel-contrib/rules_go/releases/download/v0.57.0/rules_go-v0.57.0.zip",
+        "https://github.com/bazel-contrib/rules_go/releases/download/v0.57.0/rules_go-v0.57.0.zip",
     ],
 )
 
@@ -190,7 +190,7 @@ load("@rules_oci//oci:pull.bzl", "oci_pull")
 # A multi-arch base image
 oci_pull(
     name = "linux_debian11_multiarch_base",  # Debian bullseye
-    digest = "sha256:b82f113425c5b5c714151aaacd8039bc141821cdcd3c65202d42bdf9c43ae60b",  # 2023-12-12
+    digest = "sha256:55a5e011b2c4246b4c51e01fcc2b452d151e03df052e357465f0392fcd59fddf",
     image = "gcr.io/prysmaticlabs/distroless/cc-debian11",
     platforms = [
         "linux/amd64",
@@ -208,7 +208,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()
 
 go_register_toolchains(
-    go_version = "1.24.0",
+    go_version = "1.25.1",
     nogo = "@//:nogo",
 )
 
@@ -253,16 +253,16 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.6.0-alpha.1"
+consensus_spec_version = "v1.6.0-beta.0"
 
 load("@prysm//tools:download_spectests.bzl", "consensus_spec_tests")
 
 consensus_spec_tests(
     name = "consensus_spec_tests",
     flavors = {
-        "general": "sha256-o4t9p3R+fQHF4KOykGmwlG3zDw5wUdVWprkzId8aIsk=",
-        "minimal": "sha256-sU7ToI8t3MR8x0vVjC8ERmAHZDWpEmnAC9FWIpHi5x4=",
-        "mainnet": "sha256-YKS4wngg0LgI9Upp4MYJ77aG+8+e/G4YeqEIlp06LZw=",
+        "general": "sha256-rT3jQp2+ZaDiO66gIQggetzqr+kGeexaLqEhbx4HDMY=",
+        "minimal": "sha256-wowwwyvd0KJLsE+oDOtPkrhZyJndJpJ0lbXYsLH6XBw=",
+        "mainnet": "sha256-4ZLrLNeO7NihZ4TuWH5V5fUhvW9Y3mAPBQDCqrfShps=",
     },
     version = consensus_spec_version,
 )
@@ -278,7 +278,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-Nv4TEuEJPQIM4E6T9J0FOITsmappmXZjGtlhe1HEXnU=",
+    integrity = "sha256-sBe3Rx8zGq9IrvfgIhZQpYidGjy3mE1SiCb6/+pjLdY=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
@@ -300,22 +300,6 @@ filegroup(
     url = "https://github.com/ethereum/bls12-381-tests/releases/download/%s/bls_tests_yaml.tar.gz" % bls_test_version,
 )
 
-http_archive(
-    name = "eth2_networks",
-    build_file_content = """
-filegroup(
-    name = "configs",
-    srcs = glob([
-        "shared/**/config.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    sha256 = "77e7e3ed65e33b7bb19d30131f4c2bb39e4dfeb188ab9ae84651c3cc7600131d",
-    strip_prefix = "eth2-networks-934c948e69205dcf2deb87e4ae6cc140c335f94d",
-    url = "https://github.com/eth-clients/eth2-networks/archive/934c948e69205dcf2deb87e4ae6cc140c335f94d.tar.gz",
-)
-
 http_archive(
     name = "holesky_testnet",
     build_file_content = """
@@ -327,9 +311,9 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 """,
-    integrity = "sha256-YVFFrCmjoGZ3fXMWpsCpSsYbANy1grnqYwOLKIg2SsA=",
-    strip_prefix = "holesky-32a72e21c6e53c262f27d50dd540cb654517d03a",
-    url = "https://github.com/eth-clients/holesky/archive/32a72e21c6e53c262f27d50dd540cb654517d03a.tar.gz",  # 2025-03-17
+    integrity = "sha256-htyxg8Ln2o8eCiifFN7/hcHGZg8Ir9CPzCEx+FUnnCs=",
+    strip_prefix = "holesky-8aec65f11f0c986d6b76b2eb902420635eb9b815",
+    url = "https://github.com/eth-clients/holesky/archive/8aec65f11f0c986d6b76b2eb902420635eb9b815.tar.gz",
 )
 
 http_archive(
@@ -359,9 +343,9 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 """,
-    integrity = "sha256-b5F7Wg9LLMqGRIpP2uqb/YsSFVn2ynzlV7g/Nb1EFLk=",
-    strip_prefix = "sepolia-562d9938f08675e9ba490a1dfba21fb05843f39f",
-    url = "https://github.com/eth-clients/sepolia/archive/562d9938f08675e9ba490a1dfba21fb05843f39f.tar.gz",  # 2025-03-17
+    integrity = "sha256-+UZgfvBcea0K0sbvAJZOz5ZNmxdWZYbohP38heUuc6w=",
+    strip_prefix = "sepolia-f9158732adb1a2a6440613ad2232eb50e7384c4f",
+    url = "https://github.com/eth-clients/sepolia/archive/f9158732adb1a2a6440613ad2232eb50e7384c4f.tar.gz",
 )
 
 http_archive(
@@ -375,17 +359,17 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 """,
-    integrity = "sha256-dPiEWUd8QvbYGwGtIm0QtCekitVLOLsW5rpQIGzz8PU=",
-    strip_prefix = "hoodi-828c2c940e1141092bd4bb979cef547ea926d272",
-    url = "https://github.com/eth-clients/hoodi/archive/828c2c940e1141092bd4bb979cef547ea926d272.tar.gz",
+    integrity = "sha256-G+4c9c/vci1OyPrQJnQCI+ZCv/E0cWN4hrHDY3i7ns0=",
+    strip_prefix = "hoodi-b6ee51b2045a5e7fe3efac52534f75b080b049c6",
+    url = "https://github.com/eth-clients/hoodi/archive/b6ee51b2045a5e7fe3efac52534f75b080b049c6.tar.gz",
 )
 
 http_archive(
     name = "com_google_protobuf",
-    sha256 = "9bd87b8280ef720d3240514f884e56a712f2218f0d693b48050c836028940a42",
-    strip_prefix = "protobuf-25.1",
+    sha256 = "7c3ebd7aaedd86fa5dc479a0fda803f602caaf78d8aff7ce83b89e1b8ae7442a",
+    strip_prefix = "protobuf-28.3",
     urls = [
-        "https://github.com/protocolbuffers/protobuf/archive/v25.1.tar.gz",
+        "https://github.com/protocolbuffers/protobuf/archive/v28.3.tar.gz",
     ],
 )
 

api/apiutil/BUILD.bazel

@@ -2,18 +2,28 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["common.go"],
+    srcs = [
+        "common.go",
+        "header.go",
+    ],
     importpath = "github.com/OffchainLabs/prysm/v6/api/apiutil",
     visibility = ["//visibility:public"],
-    deps = ["//consensus-types/primitives:go_default_library"],
+    deps = [
+        "//consensus-types/primitives:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["common_test.go"],
+    srcs = [
+        "common_test.go",
+        "header_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
         "//consensus-types/primitives:go_default_library",
         "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
     ],
 )

api/apiutil/header.go

@@ -0,0 +1,122 @@
+package apiutil
+
+import (
+	"mime"
+	"sort"
+	"strconv"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type mediaRange struct {
+	mt   string  // canonicalised media‑type, e.g. "application/json"
+	q    float64 // quality factor (0‑1)
+	raw  string  // original string – useful for logging/debugging
+	spec int     // 2=exact, 1=type/*, 0=*/*
+}
+
+func parseMediaRange(field string) (mediaRange, bool) {
+	field = strings.TrimSpace(field)
+
+	mt, params, err := mime.ParseMediaType(field)
+	if err != nil {
+		log.WithError(err).Debug("Failed to parse header field")
+		return mediaRange{}, false
+	}
+
+	r := mediaRange{mt: mt, q: 1, spec: 2, raw: field}
+
+	if qs, ok := params["q"]; ok {
+		v, err := strconv.ParseFloat(qs, 64)
+		if err != nil || v < 0 || v > 1 {
+			log.WithField("q", qs).Debug("Invalid quality factor (0‑1)")
+			return mediaRange{}, false // skip invalid entry
+		}
+		r.q = v
+	}
+
+	switch {
+	case mt == "*/*":
+		r.spec = 0
+	case strings.HasSuffix(mt, "/*"):
+		r.spec = 1
+	}
+	return r, true
+}
+
+func hasExplicitQ(r mediaRange) bool {
+	return strings.Contains(strings.ToLower(r.raw), ";q=")
+}
+
+// ParseAccept returns media ranges sorted by q (desc) then specificity.
+func ParseAccept(header string) []mediaRange {
+	if header == "" {
+		return []mediaRange{{mt: "*/*", q: 1, spec: 0, raw: "*/*"}}
+	}
+
+	var out []mediaRange
+	for _, field := range strings.Split(header, ",") {
+		if r, ok := parseMediaRange(field); ok {
+			out = append(out, r)
+		}
+	}
+
+	sort.SliceStable(out, func(i, j int) bool {
+		ei, ej := hasExplicitQ(out[i]), hasExplicitQ(out[j])
+		if ei != ej {
+			return ei // explicit beats implicit
+		}
+		if out[i].q != out[j].q {
+			return out[i].q > out[j].q
+		}
+		return out[i].spec > out[j].spec
+	})
+	return out
+}
+
+// Matches reports whether content type is acceptable per the header.
+func Matches(header, ct string) bool {
+	for _, r := range ParseAccept(header) {
+		switch {
+		case r.q == 0:
+			continue
+		case r.mt == "*/*":
+			return true
+		case strings.HasSuffix(r.mt, "/*"):
+			if strings.HasPrefix(ct, r.mt[:len(r.mt)-1]) {
+				return true
+			}
+		case r.mt == ct:
+			return true
+		}
+	}
+	return false
+}
+
+// Negotiate selects the best server type according to the header.
+// Returns the chosen type and true, or "", false when nothing matches.
+func Negotiate(header string, serverTypes []string) (string, bool) {
+	for _, r := range ParseAccept(header) {
+		if r.q == 0 {
+			continue
+		}
+		for _, s := range serverTypes {
+			if Matches(r.mt, s) {
+				return s, true
+			}
+		}
+	}
+	return "", false
+}
+
+// PrimaryAcceptMatches only checks if the first accept matches
+func PrimaryAcceptMatches(header, produced string) bool {
+	for _, r := range ParseAccept(header) {
+		if r.q == 0 {
+			continue // explicitly unacceptable – skip
+		}
+		return Matches(r.mt, produced)
+	}
+	return false
+}

api/apiutil/header_test.go

@@ -0,0 +1,174 @@
+package apiutil
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestParseAccept(t *testing.T) {
+	type want struct {
+		mt   string
+		q    float64
+		spec int
+	}
+
+	cases := []struct {
+		name   string
+		header string
+		want   []want
+	}{
+		{
+			name:   "empty header becomes */*;q=1",
+			header: "",
+			want:   []want{{mt: "*/*", q: 1, spec: 0}},
+		},
+		{
+			name:   "quality ordering then specificity",
+			header: "application/json;q=0.2, */*;q=0.1, application/xml;q=0.5, text/*;q=0.5",
+			want: []want{
+				{mt: "application/xml", q: 0.5, spec: 2},
+				{mt: "text/*", q: 0.5, spec: 1},
+				{mt: "application/json", q: 0.2, spec: 2},
+				{mt: "*/*", q: 0.1, spec: 0},
+			},
+		},
+		{
+			name:   "invalid pieces are skipped",
+			header: "text/plain; q=boom, application/json",
+			want:   []want{{mt: "application/json", q: 1, spec: 2}},
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := ParseAccept(tc.header)
+			gotProjected := make([]want, len(got))
+			for i, g := range got {
+				gotProjected[i] = want{mt: g.mt, q: g.q, spec: g.spec}
+			}
+			require.DeepEqual(t, gotProjected, tc.want)
+		})
+	}
+}
+
+func TestMatches(t *testing.T) {
+	cases := []struct {
+		name    string
+		accept  string
+		ct      string
+		matches bool
+	}{
+		{"exact match", "application/json", "application/json", true},
+		{"type wildcard", "application/*;q=0.8", "application/xml", true},
+		{"global wildcard", "*/*;q=0.1", "image/png", true},
+		{"explicitly unacceptable (q=0)", "text/*;q=0", "text/plain", false},
+		{"no match", "image/png", "application/json", false},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := Matches(tc.accept, tc.ct)
+			require.Equal(t, tc.matches, got)
+		})
+	}
+}
+
+func TestNegotiate(t *testing.T) {
+	cases := []struct {
+		name        string
+		accept      string
+		serverTypes []string
+		wantType    string
+		ok          bool
+	}{
+		{
+			name:        "highest quality wins",
+			accept:      "application/json;q=0.8,application/xml;q=0.9",
+			serverTypes: []string{"application/json", "application/xml"},
+			wantType:    "application/xml",
+			ok:          true,
+		},
+		{
+			name:        "wildcard matches first server type",
+			accept:      "*/*;q=0.5",
+			serverTypes: []string{"application/octet-stream", "application/json"},
+			wantType:    "application/octet-stream",
+			ok:          true,
+		},
+		{
+			name:        "no acceptable type",
+			accept:      "image/png",
+			serverTypes: []string{"application/json"},
+			wantType:    "",
+			ok:          false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := Negotiate(tc.accept, tc.serverTypes)
+			require.Equal(t, tc.ok, ok)
+			require.Equal(t, tc.wantType, got)
+		})
+	}
+}
+
+func TestPrimaryAcceptMatches(t *testing.T) {
+	tests := []struct {
+		name     string
+		accept   string
+		produced string
+		expect   bool
+	}{
+		{
+			name:     "prefers json",
+			accept:   "application/json;q=0.9,application/xml",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "wildcard application beats other wildcard",
+			accept:   "application/*;q=0.2,*/*;q=0.1",
+			produced: "application/xml",
+			expect:   true,
+		},
+		{
+			name:     "json wins",
+			accept:   "application/xml;q=0.8,application/json;q=0.9",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "json loses",
+			accept:   "application/xml;q=0.8,application/json;q=0.9,application/octet-stream;q=0.99",
+			produced: "application/json",
+			expect:   false,
+		},
+		{
+			name:     "json wins with non q option",
+			accept:   "application/xml;q=0.8,image/png,application/json;q=0.9",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "json not primary",
+			accept:   "image/png,application/json",
+			produced: "application/json",
+			expect:   false,
+		},
+		{
+			name:     "absent header",
+			accept:   "",
+			produced: "text/plain",
+			expect:   true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := PrimaryAcceptMatches(tc.accept, tc.produced)
+			require.Equal(t, got, tc.expect)
+		})
+	}
+}

api/client/beacon/BUILD.bazel

@@ -16,7 +16,6 @@ go_library(
         "//api/server/structs:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
-        "//network/forks:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",

api/client/beacon/client.go

@@ -9,7 +9,6 @@ import (
 	"net/url"
 	"path"
 	"regexp"
-	"sort"
 	"strconv"
 
 	"github.com/OffchainLabs/prysm/v6/api/client"
@@ -17,7 +16,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
@@ -137,24 +135,6 @@ func (c *Client) GetFork(ctx context.Context, stateId StateOrBlockId) (*ethpb.Fo
 	return fr.ToConsensus()
 }
 
-// GetForkSchedule retrieve all forks, past present and future, of which this node is aware.
-func (c *Client) GetForkSchedule(ctx context.Context) (forks.OrderedSchedule, error) {
-	body, err := c.Get(ctx, getForkSchedulePath)
-	if err != nil {
-		return nil, errors.Wrap(err, "error requesting fork schedule")
-	}
-	fsr := &forkScheduleResponse{}
-	err = json.Unmarshal(body, fsr)
-	if err != nil {
-		return nil, err
-	}
-	ofs, err := fsr.OrderedForkSchedule()
-	if err != nil {
-		return nil, errors.Wrap(err, fmt.Sprintf("problem unmarshaling %s response", getForkSchedulePath))
-	}
-	return ofs, nil
-}
-
 // GetConfigSpec retrieve the current configs of the network used by the beacon node.
 func (c *Client) GetConfigSpec(ctx context.Context) (*structs.GetSpecResponse, error) {
 	body, err := c.Get(ctx, getConfigSpecPath)
@@ -334,31 +314,3 @@ func (c *Client) GetBLStoExecutionChanges(ctx context.Context) (*structs.BLSToEx
 	}
 	return poolResponse, nil
 }
-
-type forkScheduleResponse struct {
-	Data []structs.Fork
-}
-
-func (fsr *forkScheduleResponse) OrderedForkSchedule() (forks.OrderedSchedule, error) {
-	ofs := make(forks.OrderedSchedule, 0)
-	for _, d := range fsr.Data {
-		epoch, err := strconv.ParseUint(d.Epoch, 10, 64)
-		if err != nil {
-			return nil, errors.Wrapf(err, "error parsing epoch %s", d.Epoch)
-		}
-		vSlice, err := hexutil.Decode(d.CurrentVersion)
-		if err != nil {
-			return nil, err
-		}
-		if len(vSlice) != 4 {
-			return nil, fmt.Errorf("got %d byte version, expected 4 bytes. version hex=%s", len(vSlice), d.CurrentVersion)
-		}
-		version := bytesutil.ToBytes4(vSlice)
-		ofs = append(ofs, forks.ForkScheduleEntry{
-			Version: version,
-			Epoch:   primitives.Epoch(epoch),
-		})
-	}
-	sort.Sort(ofs)
-	return ofs, nil
-}

api/client/builder/BUILD.bazel

@@ -50,6 +50,7 @@ go_test(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",

api/client/builder/client.go

@@ -30,10 +30,11 @@ import (
 )
 
 const (
-	getExecHeaderPath          = "/eth/v1/builder/header/{{.Slot}}/{{.ParentHash}}/{{.Pubkey}}"
-	getStatus                  = "/eth/v1/builder/status"
-	postBlindedBeaconBlockPath = "/eth/v1/builder/blinded_blocks"
-	postRegisterValidatorPath  = "/eth/v1/builder/validators"
+	getExecHeaderPath            = "/eth/v1/builder/header/{{.Slot}}/{{.ParentHash}}/{{.Pubkey}}"
+	getStatus                    = "/eth/v1/builder/status"
+	postBlindedBeaconBlockPath   = "/eth/v1/builder/blinded_blocks"
+	postBlindedBeaconBlockV2Path = "/eth/v2/builder/blinded_blocks"
+	postRegisterValidatorPath    = "/eth/v1/builder/validators"
 )
 
 var (
@@ -101,7 +102,8 @@ type BuilderClient interface {
 	NodeURL() string
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
-	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error
 	Status(ctx context.Context) error
 }
 
@@ -152,7 +154,8 @@ func (c *Client) NodeURL() string {
 type reqOption func(*http.Request)
 
 // do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder.
-func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, header http.Header, err error) {
+// It validates that the HTTP response status matches the expectedStatus parameter.
+func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, expectedStatus int, opts ...reqOption) (res []byte, header http.Header, err error) {
 	ctx, span := trace.StartSpan(ctx, "builder.client.do")
 	defer func() {
 		tracing.AnnotateError(span, err)
@@ -187,8 +190,8 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 			log.WithError(closeErr).Error("Failed to close response body")
 		}
 	}()
-	if r.StatusCode != http.StatusOK {
-		err = non200Err(r)
+	if r.StatusCode != expectedStatus {
+		err = unexpectedStatusErr(r, expectedStatus)
 		return
 	}
 	res, err = io.ReadAll(io.LimitReader(r.Body, client.MaxBodySize))
@@ -236,7 +239,7 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 			r.Header.Set("Accept", api.JsonMediaType)
 		}
 	}
-	data, header, err := c.do(ctx, http.MethodGet, path, nil, getOpts)
+	data, header, err := c.do(ctx, http.MethodGet, path, nil, http.StatusOK, getOpts)
 	if err != nil {
 		return nil, errors.Wrap(err, "error getting header from builder server")
 	}
@@ -409,7 +412,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 		}
 	}
 
-	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), postOpts); err != nil {
+	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), http.StatusOK, postOpts); err != nil {
 		return errors.Wrap(err, "do")
 	}
 	log.WithField("registrationCount", len(svr)).Debug("Successfully registered validator(s) on builder")
@@ -446,6 +449,9 @@ func sszValidatorRegisterRequest(svr []*ethpb.SignedValidatorRegistrationV1) ([]
 var errResponseVersionMismatch = errors.New("builder API response uses a different version than requested in " + api.VersionHeader + " header")
 
 func getVersionsBlockToPayload(blockVersion int) (int, error) {
+	if blockVersion >= version.Fulu {
+		return version.Fulu, nil
+	}
 	if blockVersion >= version.Deneb {
 		return version.Deneb, nil
 	}
@@ -460,7 +466,7 @@ func getVersionsBlockToPayload(blockVersion int) (int, error) {
 
 // SubmitBlindedBlock calls the builder API endpoint that binds the validator to the builder and submits the block.
 // The response is the full execution payload used to create the blinded block.
-func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	body, postOpts, err := c.buildBlindedBlockRequest(sb)
 	if err != nil {
 		return nil, nil, err
@@ -468,7 +474,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 
 	// post the blinded block - the execution payload response should contain the unblinded payload, along with the
 	// blobs bundle if it is post deneb.
-	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), postOpts)
+	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), http.StatusOK, postOpts)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "error posting the blinded block to the builder api")
 	}
@@ -498,6 +504,24 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 	return ed, blobs, nil
 }
 
+// SubmitBlindedBlockPostFulu calls the builder API endpoint post-Fulu where relays only return status codes.
+// This method is used after the Fulu fork when MEV-boost relays no longer return execution payloads.
+func (c *Client) SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error {
+	body, postOpts, err := c.buildBlindedBlockRequest(sb)
+	if err != nil {
+		return err
+	}
+
+	// Post the blinded block - the response should only contain a status code (no payload)
+	_, _, err = c.do(ctx, http.MethodPost, postBlindedBeaconBlockV2Path, bytes.NewBuffer(body), http.StatusAccepted, postOpts)
+	if err != nil {
+		return errors.Wrap(err, "error posting the blinded block to the builder api post-Fulu")
+	}
+
+	// Success is indicated by no error (status 202)
+	return nil
+}
+
 func (c *Client) checkBlockVersion(respBytes []byte, header http.Header) (int, error) {
 	var versionHeader string
 	if c.sszEnabled {
@@ -558,7 +582,7 @@ func (c *Client) buildBlindedBlockRequest(sb interfaces.ReadOnlySignedBeaconBloc
 func (c *Client) parseBlindedBlockResponse(
 	respBytes []byte,
 	forkVersion int,
-) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	if c.sszEnabled {
 		return c.parseBlindedBlockResponseSSZ(respBytes, forkVersion)
 	}
@@ -568,8 +592,18 @@ func (c *Client) parseBlindedBlockResponse(
 func (c *Client) parseBlindedBlockResponseSSZ(
 	respBytes []byte,
 	forkVersion int,
-) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
-	if forkVersion >= version.Deneb {
+) (interfaces.ExecutionData, v1.BlobsBundler, error) {
+	if forkVersion >= version.Fulu {
+		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundleV2{}
+		if err := payloadAndBlobs.UnmarshalSSZ(respBytes); err != nil {
+			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayloadDenebAndBlobsBundleV2 SSZ")
+		}
+		ed, err := blocks.NewWrappedExecutionData(payloadAndBlobs.Payload)
+		if err != nil {
+			return nil, nil, errors.Wrapf(err, "unable to wrap execution data for %s", version.String(forkVersion))
+		}
+		return ed, payloadAndBlobs.BlobsBundle, nil
+	} else if forkVersion >= version.Deneb {
 		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundle{}
 		if err := payloadAndBlobs.UnmarshalSSZ(respBytes); err != nil {
 			return nil, nil, errors.Wrap(err, "unable to unmarshal ExecutionPayloadDenebAndBlobsBundle SSZ")
@@ -644,11 +678,11 @@ func (c *Client) Status(ctx context.Context) error {
 	getOpts := func(r *http.Request) {
 		r.Header.Set("Accept", api.JsonMediaType)
 	}
-	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, getOpts)
+	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, http.StatusOK, getOpts)
 	return err
 }
 
-func non200Err(response *http.Response) error {
+func unexpectedStatusErr(response *http.Response, expected int) error {
 	bodyBytes, err := io.ReadAll(io.LimitReader(response.Body, client.MaxErrBodySize))
 	var errMessage ErrorMessage
 	var body string
@@ -657,7 +691,7 @@ func non200Err(response *http.Response) error {
 	} else {
 		body = "response body:\n" + string(bodyBytes)
 	}
-	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
+	msg := fmt.Sprintf("expected=%d, got=%d, url=%s, body=%s", expected, response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
 	case http.StatusUnsupportedMediaType:
 		log.WithError(ErrUnsupportedMediaType).Debug(msg)

api/client/builder/client_test.go

@@ -2,6 +2,7 @@ package builder
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -13,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	v1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -1553,6 +1555,89 @@ func testSignedBlindedBeaconBlockElectra(t *testing.T) *eth.SignedBlindedBeaconB
 	}
 }
 
+func TestSubmitBlindedBlockPostFulu(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("success", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockV2Path, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
+				require.Equal(t, api.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, api.JsonMediaType, r.Header.Get("Accept"))
+				// Post-Fulu: only return status code, no payload
+				return &http.Response{
+					StatusCode: http.StatusAccepted,
+					Body:       io.NopCloser(bytes.NewBufferString("")),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.NoError(t, err)
+	})
+
+	t.Run("success_ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockV2Path, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get(api.VersionHeader))
+				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
+				// Post-Fulu: only return status code, no payload
+				return &http.Response{
+					StatusCode: http.StatusAccepted,
+					Body:       io.NopCloser(bytes.NewBufferString("")),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.NoError(t, err)
+	})
+
+	t.Run("error_response", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockV2Path, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
+				message := ErrorMessage{
+					Code:    400,
+					Message: "Bad Request",
+				}
+				resp, err := json.Marshal(message)
+				require.NoError(t, err)
+				return &http.Response{
+					StatusCode: http.StatusBadRequest,
+					Body:       io.NopCloser(bytes.NewBuffer(resp)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.ErrorIs(t, err, ErrNotOK)
+	})
+}
+
 func TestRequestLogger(t *testing.T) {
 	wo := WithObserver(&requestLogger{})
 	c, err := NewClient("localhost:3500", wo)
@@ -1573,3 +1658,166 @@ func TestRequestLogger(t *testing.T) {
 	err = c.Status(ctx)
 	require.NoError(t, err)
 }
+
+func TestGetVersionsBlockToPayload(t *testing.T) {
+	tests := []struct {
+		name            string
+		blockVersion    int
+		expectedVersion int
+		expectedError   bool
+	}{
+		{
+			name:            "Fulu version",
+			blockVersion:    6, // version.Fulu
+			expectedVersion: 6,
+			expectedError:   false,
+		},
+		{
+			name:            "Deneb version",
+			blockVersion:    4, // version.Deneb
+			expectedVersion: 4,
+			expectedError:   false,
+		},
+		{
+			name:            "Capella version",
+			blockVersion:    3, // version.Capella
+			expectedVersion: 3,
+			expectedError:   false,
+		},
+		{
+			name:            "Bellatrix version",
+			blockVersion:    2, // version.Bellatrix
+			expectedVersion: 2,
+			expectedError:   false,
+		},
+		{
+			name:          "Unsupported version",
+			blockVersion:  0,
+			expectedError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			version, err := getVersionsBlockToPayload(tt.blockVersion)
+			if tt.expectedError {
+				assert.NotNil(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expectedVersion, version)
+			}
+		})
+	}
+}
+
+func TestParseBlindedBlockResponseSSZ_WithBlobsBundleV2(t *testing.T) {
+	c := &Client{sszEnabled: true}
+
+	// Create test payload
+	payload := &v1.ExecutionPayloadDeneb{
+		ParentHash:    make([]byte, 32),
+		FeeRecipient:  make([]byte, 20),
+		StateRoot:     make([]byte, 32),
+		ReceiptsRoot:  make([]byte, 32),
+		LogsBloom:     make([]byte, 256),
+		PrevRandao:    make([]byte, 32),
+		BlockNumber:   123456,
+		GasLimit:      30000000,
+		GasUsed:       21000,
+		Timestamp:     1234567890,
+		ExtraData:     []byte("test-extra-data"),
+		BaseFeePerGas: make([]byte, 32),
+		BlockHash:     make([]byte, 32),
+		Transactions:  [][]byte{},
+		Withdrawals:   []*v1.Withdrawal{},
+		BlobGasUsed:   1024,
+		ExcessBlobGas: 2048,
+	}
+
+	// Create test BlobsBundleV2
+	bundleV2 := &v1.BlobsBundleV2{
+		KzgCommitments: [][]byte{make([]byte, 48), make([]byte, 48)},
+		Proofs:         [][]byte{make([]byte, 48), make([]byte, 48)},
+		Blobs:          [][]byte{make([]byte, 131072), make([]byte, 131072)},
+	}
+
+	// Test Fulu version (should use ExecutionPayloadDenebAndBlobsBundleV2)
+	t.Run("Fulu version with BlobsBundleV2", func(t *testing.T) {
+		payloadAndBlobsV2 := &v1.ExecutionPayloadDenebAndBlobsBundleV2{
+			Payload:     payload,
+			BlobsBundle: bundleV2,
+		}
+
+		respBytes, err := payloadAndBlobsV2.MarshalSSZ()
+		require.NoError(t, err)
+
+		ed, bundle, err := c.parseBlindedBlockResponseSSZ(respBytes, 6) // version.Fulu
+		require.NoError(t, err)
+		require.NotNil(t, ed)
+		require.NotNil(t, bundle)
+
+		// Verify the bundle is BlobsBundleV2
+		bundleV2Result, ok := bundle.(*v1.BlobsBundleV2)
+		assert.Equal(t, true, ok, "Expected BlobsBundleV2 type")
+		require.Equal(t, len(bundleV2.KzgCommitments), len(bundleV2Result.KzgCommitments))
+		require.Equal(t, len(bundleV2.Proofs), len(bundleV2Result.Proofs))
+		require.Equal(t, len(bundleV2.Blobs), len(bundleV2Result.Blobs))
+	})
+
+	// Test Deneb version (should use regular BlobsBundle)
+	t.Run("Deneb version with regular BlobsBundle", func(t *testing.T) {
+		regularBundle := &v1.BlobsBundle{
+			KzgCommitments: bundleV2.KzgCommitments,
+			Proofs:         bundleV2.Proofs,
+			Blobs:          bundleV2.Blobs,
+		}
+
+		payloadAndBlobs := &v1.ExecutionPayloadDenebAndBlobsBundle{
+			Payload:     payload,
+			BlobsBundle: regularBundle,
+		}
+
+		respBytes, err := payloadAndBlobs.MarshalSSZ()
+		require.NoError(t, err)
+
+		ed, bundle, err := c.parseBlindedBlockResponseSSZ(respBytes, 4) // version.Deneb
+		require.NoError(t, err)
+		require.NotNil(t, ed)
+		require.NotNil(t, bundle)
+
+		// Verify the bundle is regular BlobsBundle
+		regularBundleResult, ok := bundle.(*v1.BlobsBundle)
+		assert.Equal(t, true, ok, "Expected BlobsBundle type")
+		require.Equal(t, len(regularBundle.KzgCommitments), len(regularBundleResult.KzgCommitments))
+	})
+
+	// Test invalid SSZ data
+	t.Run("Invalid SSZ data", func(t *testing.T) {
+		invalidBytes := []byte("invalid-ssz-data")
+
+		ed, bundle, err := c.parseBlindedBlockResponseSSZ(invalidBytes, 6)
+		assert.NotNil(t, err)
+		assert.Equal(t, true, ed == nil)
+		assert.Equal(t, true, bundle == nil)
+	})
+}
+
+func TestSubmitBlindedBlock_BlobsBundlerInterface(t *testing.T) {
+	// Note: The full integration test is complex due to version detection logic
+	// The key functionality is tested in the parseBlindedBlockResponseSSZ tests above
+	// and in the mock service tests which verify the interface changes work correctly
+
+	t.Run("Interface signature verification", func(t *testing.T) {
+		// This test verifies that the SubmitBlindedBlock method signature
+		// has been updated to return BlobsBundler interface
+
+		client := &Client{}
+
+		// Verify the method exists with the correct signature
+		// by using reflection or by checking it compiles with the interface
+		var _ func(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) = client.SubmitBlindedBlock
+
+		// This test passes if the signature is correct
+		assert.Equal(t, true, true)
+	})
+}

api/client/builder/testing/mock.go

@@ -41,10 +41,15 @@ func (m MockClient) RegisterValidator(_ context.Context, svr []*ethpb.SignedVali
 }
 
 // SubmitBlindedBlock --
-func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	return nil, nil, nil
 }
 
+// SubmitBlindedBlockPostFulu --
+func (MockClient) SubmitBlindedBlockPostFulu(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) error {
+	return nil
+}
+
 // Status --
 func (MockClient) Status(_ context.Context) error {
 	return nil

api/client/builder/types_test.go

@@ -1699,7 +1699,7 @@ func TestExecutionPayloadHeaderCapellaRoundtrip(t *testing.T) {
 	require.DeepEqual(t, string(expected[0:len(expected)-1]), string(m))
 }
 
-func TestErrorMessage_non200Err(t *testing.T) {
+func TestErrorMessage_unexpectedStatusErr(t *testing.T) {
 	mockRequest := &http.Request{
 		URL: &url.URL{Path: "example.com"},
 	}
@@ -1779,7 +1779,7 @@ func TestErrorMessage_non200Err(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			err := non200Err(tt.args)
+			err := unexpectedStatusErr(tt.args, http.StatusOK)
 			if err != nil && tt.wantMessage != "" {
 				require.ErrorContains(t, tt.wantMessage, err)
 			}

api/server/httprest/options.go

@@ -1,9 +1,8 @@
 package httprest
 
 import (
-	"time"
-
 	"net/http"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/api/server/middleware"
 )

api/server/middleware/BUILD.bazel

@@ -10,6 +10,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//api:go_default_library",
+        "//api/apiutil:go_default_library",
         "@com_github_rs_cors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],

api/server/middleware/middleware.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/OffchainLabs/prysm/v6/api"
+	"github.com/OffchainLabs/prysm/v6/api/apiutil"
 	"github.com/rs/cors"
 	log "github.com/sirupsen/logrus"
 )
@@ -74,42 +75,10 @@ func ContentTypeHandler(acceptedMediaTypes []string) Middleware {
 func AcceptHeaderHandler(serverAcceptedTypes []string) Middleware {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			acceptHeader := r.Header.Get("Accept")
-			// header is optional and should skip if not provided
-			if acceptHeader == "" {
-				next.ServeHTTP(w, r)
+			if _, ok := apiutil.Negotiate(r.Header.Get("Accept"), serverAcceptedTypes); !ok {
+				http.Error(w, "Not Acceptable", http.StatusNotAcceptable)
 				return
 			}
-
-			accepted := false
-			acceptTypes := strings.Split(acceptHeader, ",")
-			// follows rules defined in https://datatracker.ietf.org/doc/html/rfc2616#section-14.1
-			for _, acceptType := range acceptTypes {
-				acceptType = strings.TrimSpace(acceptType)
-				if acceptType == "*/*" {
-					accepted = true
-					break
-				}
-				for _, serverAcceptedType := range serverAcceptedTypes {
-					if strings.HasPrefix(acceptType, serverAcceptedType) {
-						accepted = true
-						break
-					}
-					if acceptType != "/*" && strings.HasSuffix(acceptType, "/*") && strings.HasPrefix(serverAcceptedType, acceptType[:len(acceptType)-2]) {
-						accepted = true
-						break
-					}
-				}
-				if accepted {
-					break
-				}
-			}
-
-			if !accepted {
-				http.Error(w, fmt.Sprintf("Not Acceptable: %s", acceptHeader), http.StatusNotAcceptable)
-				return
-			}
-
 			next.ServeHTTP(w, r)
 		})
 	}
@@ -127,7 +96,7 @@ func AcceptEncodingHeaderHandler() Middleware {
 			gz := gzip.NewWriter(w)
 			gzipRW := &gzipResponseWriter{gz: gz, ResponseWriter: w}
 			defer func() {
-				if !gzipRW.zipped {
+				if !gzipRW.zip {
 					return
 				}
 				if err := gz.Close(); err != nil {
@@ -143,13 +112,22 @@ func AcceptEncodingHeaderHandler() Middleware {
 type gzipResponseWriter struct {
 	gz *gzip.Writer
 	http.ResponseWriter
-	zipped bool
+	zip bool
+}
+
+func (g *gzipResponseWriter) WriteHeader(statusCode int) {
+	if strings.Contains(g.Header().Get("Content-Type"), api.JsonMediaType) {
+		// Removing the current Content-Length because zipping will change it.
+		g.Header().Del("Content-Length")
+		g.Header().Set("Content-Encoding", "gzip")
+		g.zip = true
+	}
+
+	g.ResponseWriter.WriteHeader(statusCode)
 }
 
 func (g *gzipResponseWriter) Write(b []byte) (int, error) {
-	if strings.Contains(g.Header().Get("Content-Type"), api.JsonMediaType) {
-		g.zipped = true
-		g.Header().Set("Content-Encoding", "gzip")
+	if g.zip {
 		return g.gz.Write(b)
 	}
 	return g.ResponseWriter.Write(b)

api/server/middleware/middleware_test.go

@@ -13,6 +13,23 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+// frozenHeaderRecorder allows asserting that response headers were not modified
+// after the call to WriteHeader.
+//
+// Its purpose is to have a regression test for https://github.com/OffchainLabs/prysm/pull/15499.
+type frozenHeaderRecorder struct {
+	*httptest.ResponseRecorder
+	frozenHeader http.Header
+}
+
+func (r *frozenHeaderRecorder) WriteHeader(code int) {
+	if r.frozenHeader != nil {
+		return
+	}
+	r.ResponseRecorder.WriteHeader(code)
+	r.frozenHeader = r.ResponseRecorder.Header().Clone()
+}
+
 func TestNormalizeQueryValuesHandler(t *testing.T) {
 	nextHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		_, err := w.Write([]byte("next handler"))
@@ -132,6 +149,7 @@ func TestAcceptEncodingHeaderHandler(t *testing.T) {
 	dummyContent := "Test gzip middleware content"
 	nextHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", r.Header.Get("Accept"))
+		w.WriteHeader(http.StatusOK)
 		_, err := w.Write([]byte(dummyContent))
 		require.NoError(t, err)
 	})
@@ -145,19 +163,19 @@ func TestAcceptEncodingHeaderHandler(t *testing.T) {
 		expectCompressed bool
 	}{
 		{
-			name:             "Gzip supported",
+			name:             "Accept gzip",
 			accept:           api.JsonMediaType,
 			acceptEncoding:   "gzip",
 			expectCompressed: true,
 		},
 		{
-			name:             "Multiple encodings supported",
+			name:             "Accept multiple encodings",
 			accept:           api.JsonMediaType,
 			acceptEncoding:   "deflate, gzip",
 			expectCompressed: true,
 		},
 		{
-			name:             "Gzip not supported",
+			name:             "Accept unsupported encoding",
 			accept:           api.JsonMediaType,
 			acceptEncoding:   "deflate",
 			expectCompressed: false,
@@ -183,12 +201,12 @@ func TestAcceptEncodingHeaderHandler(t *testing.T) {
 			if tt.acceptEncoding != "" {
 				req.Header.Set("Accept-Encoding", tt.acceptEncoding)
 			}
-			rr := httptest.NewRecorder()
+			rr := &frozenHeaderRecorder{ResponseRecorder: httptest.NewRecorder()}
 
 			handler.ServeHTTP(rr, req)
 
 			if tt.expectCompressed {
-				require.Equal(t, "gzip", rr.Header().Get("Content-Encoding"), "Expected Content-Encoding header to be 'gzip'")
+				require.Equal(t, "gzip", rr.frozenHeader.Get("Content-Encoding"), "Expected Content-Encoding header to be 'gzip'")
 
 				compressedBody := rr.Body.Bytes()
 				require.NotEqual(t, dummyContent, string(compressedBody), "Response body should be compressed and differ from the original")

api/server/structs/BUILD.bazel

@@ -36,6 +36,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
         "//container/slice:go_default_library",
+        "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
         "//proto/engine/v1:go_default_library",

api/server/structs/conversions.go

@@ -10,6 +10,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/validator"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
+	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/math"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -699,6 +700,11 @@ func (m *SyncCommitteeMessage) ToConsensus() (*eth.SyncCommitteeMessage, error)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Signature")
 	}
+	// Add validation to check if the signature is valid BLS format
+	_, err = bls.SignatureFromBytes(sig)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
 
 	return &eth.SyncCommitteeMessage{
 		Slot:           primitives.Slot(slot),

api/server/structs/endpoints_beacon.go

@@ -283,3 +283,16 @@ type GetPendingPartialWithdrawalsResponse struct {
 	Finalized           bool                        `json:"finalized"`
 	Data                []*PendingPartialWithdrawal `json:"data"`
 }
+
+type GetProposerLookaheadResponse struct {
+	Version             string   `json:"version"`
+	ExecutionOptimistic bool     `json:"execution_optimistic"`
+	Finalized           bool     `json:"finalized"`
+	Data                []string `json:"data"` // validator indexes
+}
+
+type GetBlobsResponse struct {
+	ExecutionOptimistic bool     `json:"execution_optimistic"`
+	Finalized           bool     `json:"finalized"`
+	Data                []string `json:"data"` //blobs
+}

api/server/structs/endpoints_debug.go

@@ -56,3 +56,19 @@ type ForkChoiceNodeExtraData struct {
 	TimeStamp                string `json:"timestamp"`
 	Target                   string `json:"target"`
 }
+
+type GetDebugDataColumnSidecarsResponse struct {
+	Version             string               `json:"version"`
+	ExecutionOptimistic bool                 `json:"execution_optimistic"`
+	Finalized           bool                 `json:"finalized"`
+	Data                []*DataColumnSidecar `json:"data"`
+}
+
+type DataColumnSidecar struct {
+	Index                        string                   `json:"index"`
+	Column                       []string                 `json:"column"`
+	KzgCommitments               []string                 `json:"kzg_commitments"`
+	KzgProofs                    []string                 `json:"kzg_proofs"`
+	SignedBeaconBlockHeader      *SignedBeaconBlockHeader `json:"signed_block_header"`
+	KzgCommitmentsInclusionProof []string                 `json:"kzg_commitments_inclusion_proof"`
+}

api/server/structs/endpoints_node.go

@@ -27,6 +27,8 @@ type Identity struct {
 type Metadata struct {
 	SeqNumber string `json:"seq_number"`
 	Attnets   string `json:"attnets"`
+	Syncnets  string `json:"syncnets,omitempty"`
+	Cgc       string `json:"custody_group_count,omitempty"`
 }
 
 type GetPeerResponse struct {

beacon-chain/blockchain/BUILD.bazel

@@ -27,7 +27,7 @@ go_library(
         "receive_block.go",
         "receive_data_column.go",
         "service.go",
-        "setup_forchoice.go",
+        "setup_forkchoice.go",
         "tracked_proposer.go",
         "weak_subjectivity_checks.go",
     ],
@@ -50,7 +50,6 @@ go_library(
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
@@ -63,6 +62,7 @@ go_library(
         "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/light-client:go_default_library",
         "//beacon-chain/operations/attestations:go_default_library",
         "//beacon-chain/operations/blstoexec:go_default_library",
         "//beacon-chain/operations/slashings:go_default_library",
@@ -73,6 +73,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -147,7 +148,6 @@ go_test(
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
@@ -160,6 +160,7 @@ go_test(
         "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/light-client:go_default_library",
         "//beacon-chain/operations/attestations:go_default_library",
         "//beacon-chain/operations/attestations/kv:go_default_library",
         "//beacon-chain/operations/blstoexec:go_default_library",
@@ -181,6 +182,7 @@ go_test(
         "//container/trie:go_default_library",
         "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//genesis:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
@@ -194,6 +196,7 @@ go_test(
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_ethereum_go_ethereum//core/types:go_default_library",
         "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",

beacon-chain/blockchain/chain_info_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
@@ -624,6 +625,7 @@ func Test_hashForGenesisRoot(t *testing.T) {
 	ctx := t.Context()
 	c := setupBeaconChain(t, beaconDB)
 	st, _ := util.DeterministicGenesisStateElectra(t, 10)
+	genesis.StoreDuringTest(t, genesis.GenesisData{State: st})
 	require.NoError(t, c.cfg.BeaconDB.SaveGenesisData(ctx, st))
 	root, err := beaconDB.GenesisBlockRoot(ctx)
 	require.NoError(t, err)

beacon-chain/blockchain/currently_syncing_block.go

@@ -7,10 +7,15 @@ type currentlySyncingBlock struct {
 	roots map[[32]byte]struct{}
 }
 
-func (b *currentlySyncingBlock) set(root [32]byte) {
+func (b *currentlySyncingBlock) set(root [32]byte) error {
 	b.Lock()
 	defer b.Unlock()
+	_, ok := b.roots[root]
+	if ok {
+		return errBlockBeingSynced
+	}
 	b.roots[root] = struct{}{}
+	return nil
 }
 
 func (b *currentlySyncingBlock) unset(root [32]byte) {

beacon-chain/blockchain/error.go

@@ -44,6 +44,8 @@ var (
 	errMaxBlobsExceeded = verification.AsVerificationFailure(errors.New("expected commitments in block exceeds MAX_BLOBS_PER_BLOCK"))
 	// errMaxDataColumnsExceeded is returned when the number of data columns exceeds the maximum allowed.
 	errMaxDataColumnsExceeded = verification.AsVerificationFailure(errors.New("expected data columns for node exceeds NUMBER_OF_COLUMNS"))
+	// errBlockBeingSynced is returned when a block is being synced.
+	errBlockBeingSynced = errors.New("block is being synced")
 )
 
 // An invalid block is the block that fails state transition based on the core protocol rules.

beacon-chain/blockchain/execution_engine.go

@@ -16,7 +16,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	consensusblocks "github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	blocktypes "github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	payloadattribute "github.com/OffchainLabs/prysm/v6/consensus-types/payload-attribute"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -174,6 +174,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
 		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), arg.headBlock, arg.headRoot, nextSlot)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),
@@ -217,24 +218,18 @@ func (s *Service) getPayloadHash(ctx context.Context, root []byte) ([32]byte, er
 
 // notifyNewPayload signals execution engine on a new payload.
 // It returns true if the EL has returned VALID for the block
-func (s *Service) notifyNewPayload(ctx context.Context, preStateVersion int,
-	preStateHeader interfaces.ExecutionData, blk interfaces.ReadOnlySignedBeaconBlock) (bool, error) {
+// stVersion should represent the version of the pre-state; header should also be from the pre-state.
+func (s *Service) notifyNewPayload(ctx context.Context, stVersion int, header interfaces.ExecutionData, blk blocktypes.ROBlock) (bool, error) {
 	ctx, span := trace.StartSpan(ctx, "blockChain.notifyNewPayload")
 	defer span.End()
 
 	// Execution payload is only supported in Bellatrix and beyond. Pre
 	// merge blocks are never optimistic
-	if blk == nil {
-		return false, errors.New("signed beacon block can't be nil")
-	}
-	if preStateVersion < version.Bellatrix {
+	if stVersion < version.Bellatrix {
 		return true, nil
 	}
-	if err := consensusblocks.BeaconBlockIsNil(blk); err != nil {
-		return false, err
-	}
 	body := blk.Block().Body()
-	enabled, err := blocks.IsExecutionEnabledUsingHeader(preStateHeader, body)
+	enabled, err := blocks.IsExecutionEnabledUsingHeader(header, body)
 	if err != nil {
 		return false, errors.Wrap(invalidBlock{error: err}, "could not determine if execution is enabled")
 	}
@@ -267,28 +262,32 @@ func (s *Service) notifyNewPayload(ctx context.Context, preStateVersion int,
 			return false, errors.New("nil execution requests")
 		}
 	}
-	lastValidHash, err = s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload, versionedHashes, parentRoot, requests)
 
-	switch {
-	case err == nil:
+	lastValidHash, err = s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload, versionedHashes, parentRoot, requests)
+	if err == nil {
 		newPayloadValidNodeCount.Inc()
 		return true, nil
-	case errors.Is(err, execution.ErrAcceptedSyncingPayloadStatus):
+	}
+	logFields := logrus.Fields{
+		"slot":             blk.Block().Slot(),
+		"parentRoot":       fmt.Sprintf("%#x", parentRoot),
+		"root":             fmt.Sprintf("%#x", blk.Root()),
+		"payloadBlockHash": fmt.Sprintf("%#x", bytesutil.Trunc(payload.BlockHash())),
+	}
+	if errors.Is(err, execution.ErrAcceptedSyncingPayloadStatus) {
 		newPayloadOptimisticNodeCount.Inc()
-		log.WithFields(logrus.Fields{
-			"slot":             blk.Block().Slot(),
-			"payloadBlockHash": fmt.Sprintf("%#x", bytesutil.Trunc(payload.BlockHash())),
-		}).Info("Called new payload with optimistic block")
+		log.WithFields(logFields).Info("Called new payload with optimistic block")
 		return false, nil
-	case errors.Is(err, execution.ErrInvalidPayloadStatus):
-		lvh := bytesutil.ToBytes32(lastValidHash)
+	}
+	if errors.Is(err, execution.ErrInvalidPayloadStatus) {
+		log.WithFields(logFields).WithError(err).Error("Invalid payload status")
 		return false, invalidBlock{
 			error:         ErrInvalidPayload,
-			lastValidHash: lvh,
+			lastValidHash: bytesutil.ToBytes32(lastValidHash),
 		}
-	default:
-		return false, errors.WithMessage(ErrUndefinedExecutionEngineError, err.Error())
 	}
+	log.WithFields(logFields).WithError(err).Error("Unexpected execution engine error")
+	return false, errors.WithMessage(ErrUndefinedExecutionEngineError, err.Error())
 }
 
 // reportInvalidBlock deals with the event that an invalid block was detected by the execution layer

beacon-chain/blockchain/execution_engine_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	v1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
@@ -309,6 +310,7 @@ func Test_NotifyForkchoiceUpdate_NIlLVH(t *testing.T) {
 		block: wba,
 	}
 
+	genesis.StoreStateDuringTest(t, st)
 	require.NoError(t, beaconDB.SaveState(ctx, st, bra))
 	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, bra))
 	a := &fcuConfig{
@@ -403,6 +405,7 @@ func Test_NotifyForkchoiceUpdateRecursive_DoublyLinkedTree(t *testing.T) {
 	require.NoError(t, err)
 
 	bState, _ := util.DeterministicGenesisState(t, 10)
+	genesis.StoreStateDuringTest(t, bState)
 	require.NoError(t, beaconDB.SaveState(ctx, bState, bra))
 	require.NoError(t, fcs.InsertNode(ctx, state, blkRoot))
 	state, blkRoot, err = prepareForkchoiceState(ctx, 2, brb, bra, [32]byte{'B'}, ojc, ofc)
@@ -478,33 +481,12 @@ func Test_NotifyNewPayload(t *testing.T) {
 	phase0State, _ := util.DeterministicGenesisState(t, 1)
 	altairState, _ := util.DeterministicGenesisStateAltair(t, 1)
 	bellatrixState, _ := util.DeterministicGenesisStateBellatrix(t, 2)
-	a := &ethpb.SignedBeaconBlockAltair{
-		Block: &ethpb.BeaconBlockAltair{
-			Body: &ethpb.BeaconBlockBodyAltair{},
-		},
-	}
+	a := util.NewBeaconBlockAltair()
 	altairBlk, err := consensusblocks.NewSignedBeaconBlock(a)
 	require.NoError(t, err)
-	blk := &ethpb.SignedBeaconBlockBellatrix{
-		Block: &ethpb.BeaconBlockBellatrix{
-			Slot: 1,
-			Body: &ethpb.BeaconBlockBodyBellatrix{
-				ExecutionPayload: &v1.ExecutionPayload{
-					BlockNumber:   1,
-					ParentHash:    make([]byte, fieldparams.RootLength),
-					FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
-					StateRoot:     make([]byte, fieldparams.RootLength),
-					ReceiptsRoot:  make([]byte, fieldparams.RootLength),
-					LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
-					PrevRandao:    make([]byte, fieldparams.RootLength),
-					ExtraData:     make([]byte, 0),
-					BaseFeePerGas: make([]byte, fieldparams.RootLength),
-					BlockHash:     make([]byte, fieldparams.RootLength),
-					Transactions:  make([][]byte, 0),
-				},
-			},
-		},
-	}
+	blk := util.NewBeaconBlockBellatrix()
+	blk.Block.Slot = 1
+	blk.Block.Body.ExecutionPayload.BlockNumber = 1
 	bellatrixBlk, err := consensusblocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlockBellatrix(blk))
 	require.NoError(t, err)
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
@@ -541,12 +523,6 @@ func Test_NotifyNewPayload(t *testing.T) {
 			blk:            altairBlk,
 			isValidPayload: true,
 		},
-		{
-			name:           "nil beacon block",
-			postState:      bellatrixState,
-			errString:      "signed beacon block can't be nil",
-			isValidPayload: false,
-		},
 		{
 			name:           "new payload with optimistic block",
 			postState:      bellatrixState,
@@ -573,15 +549,8 @@ func Test_NotifyNewPayload(t *testing.T) {
 			name:      "altair pre state, happy case",
 			postState: bellatrixState,
 			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				blk := &ethpb.SignedBeaconBlockBellatrix{
-					Block: &ethpb.BeaconBlockBellatrix{
-						Body: &ethpb.BeaconBlockBodyBellatrix{
-							ExecutionPayload: &v1.ExecutionPayload{
-								ParentHash: bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength),
-							},
-						},
-					},
-				}
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Body.ExecutionPayload.ParentHash = bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength)
 				b, err := consensusblocks.NewSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
@@ -592,24 +561,7 @@ func Test_NotifyNewPayload(t *testing.T) {
 			name:      "not at merge transition",
 			postState: bellatrixState,
 			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				blk := &ethpb.SignedBeaconBlockBellatrix{
-					Block: &ethpb.BeaconBlockBellatrix{
-						Body: &ethpb.BeaconBlockBodyBellatrix{
-							ExecutionPayload: &v1.ExecutionPayload{
-								ParentHash:    make([]byte, fieldparams.RootLength),
-								FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
-								StateRoot:     make([]byte, fieldparams.RootLength),
-								ReceiptsRoot:  make([]byte, fieldparams.RootLength),
-								LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
-								PrevRandao:    make([]byte, fieldparams.RootLength),
-								ExtraData:     make([]byte, 0),
-								BaseFeePerGas: make([]byte, fieldparams.RootLength),
-								BlockHash:     make([]byte, fieldparams.RootLength),
-								Transactions:  make([][]byte, 0),
-							},
-						},
-					},
-				}
+				blk := util.NewBeaconBlockBellatrix()
 				b, err := consensusblocks.NewSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
@@ -620,15 +572,8 @@ func Test_NotifyNewPayload(t *testing.T) {
 			name:      "happy case",
 			postState: bellatrixState,
 			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				blk := &ethpb.SignedBeaconBlockBellatrix{
-					Block: &ethpb.BeaconBlockBellatrix{
-						Body: &ethpb.BeaconBlockBodyBellatrix{
-							ExecutionPayload: &v1.ExecutionPayload{
-								ParentHash: bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength),
-							},
-						},
-					},
-				}
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Body.ExecutionPayload.ParentHash = bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength)
 				b, err := consensusblocks.NewSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
@@ -639,15 +584,8 @@ func Test_NotifyNewPayload(t *testing.T) {
 			name:      "undefined error from ee",
 			postState: bellatrixState,
 			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				blk := &ethpb.SignedBeaconBlockBellatrix{
-					Block: &ethpb.BeaconBlockBellatrix{
-						Body: &ethpb.BeaconBlockBodyBellatrix{
-							ExecutionPayload: &v1.ExecutionPayload{
-								ParentHash: bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength),
-							},
-						},
-					},
-				}
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Body.ExecutionPayload.ParentHash = bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength)
 				b, err := consensusblocks.NewSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
@@ -659,15 +597,8 @@ func Test_NotifyNewPayload(t *testing.T) {
 			name:      "invalid block hash error from ee",
 			postState: bellatrixState,
 			blk: func() interfaces.ReadOnlySignedBeaconBlock {
-				blk := &ethpb.SignedBeaconBlockBellatrix{
-					Block: &ethpb.BeaconBlockBellatrix{
-						Body: &ethpb.BeaconBlockBodyBellatrix{
-							ExecutionPayload: &v1.ExecutionPayload{
-								ParentHash: bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength),
-							},
-						},
-					},
-				}
+				blk := util.NewBeaconBlockBellatrix()
+				blk.Block.Body.ExecutionPayload.ParentHash = bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength)
 				b, err := consensusblocks.NewSignedBeaconBlock(blk)
 				require.NoError(t, err)
 				return b
@@ -698,7 +629,9 @@ func Test_NotifyNewPayload(t *testing.T) {
 			require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
 			postVersion, postHeader, err := getStateVersionAndPayload(tt.postState)
 			require.NoError(t, err)
-			isValidPayload, err := service.notifyNewPayload(ctx, postVersion, postHeader, tt.blk)
+			rob, err := consensusblocks.NewROBlock(tt.blk)
+			require.NoError(t, err)
+			isValidPayload, err := service.notifyNewPayload(ctx, postVersion, postHeader, rob)
 			if tt.errString != "" {
 				require.ErrorContains(t, tt.errString, err)
 				if tt.invalidBlock {
@@ -722,17 +655,12 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	ctx := tr.ctx
 
 	bellatrixState, _ := util.DeterministicGenesisStateBellatrix(t, 2)
-	blk := &ethpb.SignedBeaconBlockBellatrix{
-		Block: &ethpb.BeaconBlockBellatrix{
-			Body: &ethpb.BeaconBlockBodyBellatrix{
-				ExecutionPayload: &v1.ExecutionPayload{
-					ParentHash: bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength),
-				},
-			},
-		},
-	}
+	blk := util.NewBeaconBlockBellatrix()
+	blk.Block.Body.ExecutionPayload.ParentHash = bytesutil.PadTo([]byte{'a'}, fieldparams.RootLength)
 	bellatrixBlk, err := consensusblocks.NewSignedBeaconBlock(blk)
 	require.NoError(t, err)
+	rob, err := consensusblocks.NewROBlock(bellatrixBlk)
+	require.NoError(t, err)
 	e := &mockExecution.EngineClient{BlockByHashMap: map[[32]byte]*v1.ExecutionBlock{}}
 	e.BlockByHashMap[[32]byte{'a'}] = &v1.ExecutionBlock{
 		Header: gethtypes.Header{
@@ -749,7 +677,7 @@ func Test_NotifyNewPayload_SetOptimisticToValid(t *testing.T) {
 	service.cfg.ExecutionEngineCaller = e
 	postVersion, postHeader, err := getStateVersionAndPayload(bellatrixState)
 	require.NoError(t, err)
-	validated, err := service.notifyNewPayload(ctx, postVersion, postHeader, bellatrixBlk)
+	validated, err := service.notifyNewPayload(ctx, postVersion, postHeader, rob)
 	require.NoError(t, err)
 	require.Equal(t, true, validated)
 }

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -102,8 +102,6 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 		log.WithError(err).Error("Could not save head")
 	}
 
-	go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), args.headBlock, args.headRoot, s.CurrentSlot()+1)
-
 	// Only need to prune attestations from pool if the head has changed.
 	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)
 	return nil

beacon-chain/blockchain/kzg/kzg.go

@@ -14,7 +14,10 @@ const BytesPerBlob = ckzg4844.BytesPerBlob
 type Blob [BytesPerBlob]byte
 
 // BytesPerCell is the number of bytes in a single cell.
-const BytesPerCell = ckzg4844.BytesPerCell
+const (
+	BytesPerCell  = ckzg4844.BytesPerCell
+	BytesPerProof = ckzg4844.BytesPerProof
+)
 
 // Cell represents a chunk of an encoded Blob.
 type Cell [BytesPerCell]byte
@@ -23,7 +26,7 @@ type Cell [BytesPerCell]byte
 type Commitment [48]byte
 
 // Proof represents a KZG proof that attests to the validity of a Blob or parts of it.
-type Proof [48]byte
+type Proof [BytesPerProof]byte
 
 // Bytes48 is a 48-byte array.
 type Bytes48 = ckzg4844.Bytes48
@@ -102,7 +105,6 @@ func VerifyCellKZGProofBatch(commitmentsBytes []Bytes48, cellIndices []uint64, c
 	for i := range cells {
 		ckzgCells[i] = ckzg4844.Cell(cells[i])
 	}
-
 	return ckzg4844.VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, ckzgCells, proofsBytes)
 }
 

beacon-chain/blockchain/kzg/trusted_setup.go

@@ -11,7 +11,7 @@ import (
 )
 
 var (
-	// https://github.com/ethereum/consensus-specs/blob/dev/presets/mainnet/trusted_setups/trusted_setup_4096.json
+	// https://github.com/ethereum/consensus-specs/blob/master/presets/mainnet/trusted_setups/trusted_setup_4096.json
 	//go:embed trusted_setup_4096.json
 	embeddedTrustedSetup []byte // 1.2Mb
 	kzgContext           *GoKZG.Context

beacon-chain/blockchain/kzg/validation.go

@@ -1,32 +1,14 @@
 package kzg
 
 import (
+	"fmt"
+
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	ckzg4844 "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/pkg/errors"
 )
 
-// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
-func Verify(sidecars ...blocks.ROBlob) error {
-	if len(sidecars) == 0 {
-		return nil
-	}
-	if len(sidecars) == 1 {
-		return kzgContext.VerifyBlobKZGProof(
-			bytesToBlob(sidecars[0].Blob),
-			bytesToCommitment(sidecars[0].KzgCommitment),
-			bytesToKZGProof(sidecars[0].KzgProof))
-	}
-	blobs := make([]GoKZG.Blob, len(sidecars))
-	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
-	proofs := make([]GoKZG.KZGProof, len(sidecars))
-	for i, sidecar := range sidecars {
-		blobs[i] = *bytesToBlob(sidecar.Blob)
-		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
-		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
-	}
-	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
-}
-
 func bytesToBlob(blob []byte) *GoKZG.Blob {
 	var ret GoKZG.Blob
 	copy(ret[:], blob)
@@ -42,3 +24,144 @@ func bytesToKZGProof(proof []byte) (ret GoKZG.KZGProof) {
 	copy(ret[:], proof)
 	return
 }
+
+// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
+func Verify(blobSidecars ...blocks.ROBlob) error {
+	if len(blobSidecars) == 0 {
+		return nil
+	}
+	if len(blobSidecars) == 1 {
+		return kzgContext.VerifyBlobKZGProof(
+			bytesToBlob(blobSidecars[0].Blob),
+			bytesToCommitment(blobSidecars[0].KzgCommitment),
+			bytesToKZGProof(blobSidecars[0].KzgProof))
+	}
+	blobs := make([]GoKZG.Blob, len(blobSidecars))
+	cmts := make([]GoKZG.KZGCommitment, len(blobSidecars))
+	proofs := make([]GoKZG.KZGProof, len(blobSidecars))
+	for i, sidecar := range blobSidecars {
+		blobs[i] = *bytesToBlob(sidecar.Blob)
+		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
+		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
+	}
+	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
+}
+
+// VerifyBlobKZGProofBatch verifies KZG proofs for multiple blobs using batch verification.
+// This is more efficient than verifying each blob individually when len(blobs) > 1.
+// For single blob verification, it uses the optimized single verification path.
+func VerifyBlobKZGProofBatch(blobs [][]byte, commitments [][]byte, proofs [][]byte) error {
+	if len(blobs) != len(commitments) || len(blobs) != len(proofs) {
+		return errors.Errorf("number of blobs (%d), commitments (%d), and proofs (%d) must match", len(blobs), len(commitments), len(proofs))
+	}
+
+	if len(blobs) == 0 {
+		return nil
+	}
+
+	// Optimize for single blob case - use single verification to avoid batch overhead
+	if len(blobs) == 1 {
+		return kzgContext.VerifyBlobKZGProof(
+			bytesToBlob(blobs[0]),
+			bytesToCommitment(commitments[0]),
+			bytesToKZGProof(proofs[0]))
+	}
+
+	// Use batch verification for multiple blobs
+	ckzgBlobs := make([]ckzg4844.Blob, len(blobs))
+	ckzgCommitments := make([]ckzg4844.Bytes48, len(commitments))
+	ckzgProofs := make([]ckzg4844.Bytes48, len(proofs))
+
+	for i := range blobs {
+		if len(blobs[i]) != len(ckzg4844.Blob{}) {
+			return fmt.Errorf("blobs len (%d) differs from expected (%d)", len(blobs[i]), len(ckzg4844.Blob{}))
+		}
+		if len(commitments[i]) != len(ckzg4844.Bytes48{}) {
+			return fmt.Errorf("commitments len (%d) differs from expected (%d)", len(commitments[i]), len(ckzg4844.Blob{}))
+		}
+		if len(proofs[i]) != len(ckzg4844.Bytes48{}) {
+			return fmt.Errorf("proofs len (%d) differs from expected (%d)", len(proofs[i]), len(ckzg4844.Blob{}))
+		}
+		ckzgBlobs[i] = ckzg4844.Blob(blobs[i])
+		ckzgCommitments[i] = ckzg4844.Bytes48(commitments[i])
+		ckzgProofs[i] = ckzg4844.Bytes48(proofs[i])
+	}
+
+	valid, err := ckzg4844.VerifyBlobKZGProofBatch(ckzgBlobs, ckzgCommitments, ckzgProofs)
+	if err != nil {
+		return errors.Wrap(err, "batch verification")
+	}
+	if !valid {
+		return errors.New("batch KZG proof verification failed")
+	}
+
+	return nil
+}
+
+// VerifyCellKZGProofBatchFromBlobData verifies cell KZG proofs in batch format directly from blob data.
+// This is more efficient than reconstructing data column sidecars when you have the raw blob data and cell proofs.
+// For PeerDAS/Fulu, the execution client provides cell proofs in flattened format via BlobsBundleV2.
+// For single blob verification, it optimizes by computing cells once and verifying efficiently.
+func VerifyCellKZGProofBatchFromBlobData(blobs [][]byte, commitments [][]byte, cellProofs [][]byte, numberOfColumns uint64) error {
+	blobCount := uint64(len(blobs))
+	expectedCellProofs := blobCount * numberOfColumns
+
+	if uint64(len(cellProofs)) != expectedCellProofs {
+		return errors.Errorf("expected %d cell proofs, got %d", expectedCellProofs, len(cellProofs))
+	}
+
+	if len(commitments) != len(blobs) {
+		return errors.Errorf("number of commitments (%d) must match number of blobs (%d)", len(commitments), len(blobs))
+	}
+
+	if blobCount == 0 {
+		return nil
+	}
+
+	// Handle multiple blobs - compute cells for all blobs
+	allCells := make([]Cell, 0, expectedCellProofs)
+	allCommitments := make([]Bytes48, 0, expectedCellProofs)
+	allIndices := make([]uint64, 0, expectedCellProofs)
+	allProofs := make([]Bytes48, 0, expectedCellProofs)
+
+	for blobIndex := range blobs {
+		if len(blobs[blobIndex]) != len(Blob{}) {
+			return fmt.Errorf("blobs len (%d) differs from expected (%d)", len(blobs[blobIndex]), len(Blob{}))
+		}
+		// Convert blob to kzg.Blob type
+		blob := Blob(blobs[blobIndex])
+
+		// Compute cells for this blob
+		cells, err := ComputeCells(&blob)
+		if err != nil {
+			return errors.Wrapf(err, "failed to compute cells for blob %d", blobIndex)
+		}
+
+		// Add cells and corresponding data for each column
+		for columnIndex := range numberOfColumns {
+			cellProofIndex := uint64(blobIndex)*numberOfColumns + columnIndex
+			if len(commitments[blobIndex]) != len(Bytes48{}) {
+				return fmt.Errorf("commitments len (%d) differs from expected (%d)", len(commitments[blobIndex]), len(Bytes48{}))
+			}
+			if len(cellProofs[cellProofIndex]) != len(Bytes48{}) {
+				return fmt.Errorf("proofs len (%d) differs from expected (%d)", len(cellProofs[cellProofIndex]), len(Bytes48{}))
+			}
+			allCells = append(allCells, cells[columnIndex])
+			allCommitments = append(allCommitments, Bytes48(commitments[blobIndex]))
+			allIndices = append(allIndices, columnIndex)
+
+			allProofs = append(allProofs, Bytes48(cellProofs[cellProofIndex]))
+		}
+	}
+
+	// Batch verify all cells
+	valid, err := VerifyCellKZGProofBatch(allCommitments, allIndices, allCells, allProofs)
+	if err != nil {
+		return errors.Wrap(err, "cell batch verification")
+	}
+	if !valid {
+		return errors.New("cell KZG proof batch verification failed")
+	}
+
+	return nil
+}

beacon-chain/blockchain/kzg/validation_test.go

@@ -22,8 +22,8 @@ func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZG
 }
 
 func TestVerify(t *testing.T) {
-	sidecars := make([]blocks.ROBlob, 0)
-	require.NoError(t, Verify(sidecars...))
+	blobSidecars := make([]blocks.ROBlob, 0)
+	require.NoError(t, Verify(blobSidecars...))
 }
 
 func TestBytesToAny(t *testing.T) {
@@ -37,6 +37,7 @@ func TestBytesToAny(t *testing.T) {
 }
 
 func TestGenerateCommitmentAndProof(t *testing.T) {
+	require.NoError(t, Start())
 	blob := random.GetRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
@@ -45,3 +46,432 @@ func TestGenerateCommitmentAndProof(t *testing.T) {
 	require.Equal(t, expectedCommitment, commitment)
 	require.Equal(t, expectedProof, proof)
 }
+
+func TestVerifyBlobKZGProofBatch(t *testing.T) {
+	// Initialize KZG for testing
+	require.NoError(t, Start())
+
+	t.Run("valid single blob batch", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+		proofs := [][]byte{proof[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.NoError(t, err)
+	})
+
+	t.Run("valid multiple blob batch", func(t *testing.T) {
+		blobCount := 3
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		proofs := make([][]byte, blobCount)
+
+		for i := 0; i < blobCount; i++ {
+			blob := random.GetRandBlob(int64(i))
+			commitment, proof, err := GenerateCommitmentAndProof(blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+			proofs[i] = proof[:]
+		}
+
+		err := VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.NoError(t, err)
+	})
+
+	t.Run("empty inputs should pass", func(t *testing.T) {
+		err := VerifyBlobKZGProofBatch([][]byte{}, [][]byte{}, [][]byte{})
+		require.NoError(t, err)
+	})
+
+	t.Run("mismatched input lengths", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Test different mismatch scenarios
+		err = VerifyBlobKZGProofBatch(
+			[][]byte{blob[:]},
+			[][]byte{},
+			[][]byte{proof[:]},
+		)
+		require.ErrorContains(t, "number of blobs (1), commitments (0), and proofs (1) must match", err)
+
+		err = VerifyBlobKZGProofBatch(
+			[][]byte{blob[:], blob[:]},
+			[][]byte{commitment[:]},
+			[][]byte{proof[:], proof[:]},
+		)
+		require.ErrorContains(t, "number of blobs (2), commitments (1), and proofs (2) must match", err)
+	})
+
+	t.Run("invalid commitment should fail", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		_, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Use a different blob's commitment (mismatch)
+		differentBlob := random.GetRandBlob(456)
+		wrongCommitment, _, err := GenerateCommitmentAndProof(differentBlob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{wrongCommitment[:]}
+		proofs := [][]byte{proof[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		// Single blob optimization uses different error message
+		require.ErrorContains(t, "can't verify opening proof", err)
+	})
+
+	t.Run("invalid proof should fail", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, _, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Use wrong proof
+		invalidProof := make([]byte, 48) // All zeros
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+		proofs := [][]byte{invalidProof}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "short buffer", err)
+	})
+
+	t.Run("mixed valid and invalid proofs should fail", func(t *testing.T) {
+		// First blob - valid
+		blob1 := random.GetRandBlob(123)
+		commitment1, proof1, err := GenerateCommitmentAndProof(blob1)
+		require.NoError(t, err)
+
+		// Second blob - invalid proof
+		blob2 := random.GetRandBlob(456)
+		commitment2, _, err := GenerateCommitmentAndProof(blob2)
+		require.NoError(t, err)
+		invalidProof := make([]byte, 48) // All zeros
+
+		blobs := [][]byte{blob1[:], blob2[:]}
+		commitments := [][]byte{commitment1[:], commitment2[:]}
+		proofs := [][]byte{proof1[:], invalidProof}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "batch verification", err)
+	})
+
+	t.Run("batch KZG proof verification failed", func(t *testing.T) {
+		// Create multiple blobs with mismatched commitments and proofs to trigger batch verification failure
+		blob1 := random.GetRandBlob(123)
+		blob2 := random.GetRandBlob(456)
+
+		// Generate valid proof for blob1
+		commitment1, proof1, err := GenerateCommitmentAndProof(blob1)
+		require.NoError(t, err)
+
+		// Generate valid proof for blob2 but use wrong commitment (from blob1)
+		_, proof2, err := GenerateCommitmentAndProof(blob2)
+		require.NoError(t, err)
+
+		// Use blob2 data with blob1's commitment and blob2's proof - this should cause batch verification to fail
+		blobs := [][]byte{blob1[:], blob2[:]}
+		commitments := [][]byte{commitment1[:], commitment1[:]} // Wrong commitment for blob2
+		proofs := [][]byte{proof1[:], proof2[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "batch KZG proof verification failed", err)
+	})
+}
+
+func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
+	// Initialize KZG for testing
+	require.NoError(t, Start())
+
+	t.Run("valid single blob cell verification", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Generate blob and commitment
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		// Compute cells and proofs
+		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Create flattened cell proofs (like execution client format)
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.NoError(t, err)
+	})
+
+	t.Run("valid multiple blob cell verification", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		for i := range blobCount {
+			// Generate blob and commitment
+			randBlob := random.GetRandBlob(int64(i))
+			var blob Blob
+			copy(blob[:], randBlob[:])
+			commitment, err := BlobToKZGCommitment(&blob)
+			require.NoError(t, err)
+
+			// Compute cells and proofs
+			cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+
+			// Add cell proofs for this blob
+			for j := range numberOfColumns {
+				allCellProofs = append(allCellProofs, cellsAndProofs.Proofs[j][:])
+			}
+		}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.NoError(t, err)
+	})
+
+	t.Run("empty inputs should pass", func(t *testing.T) {
+		err := VerifyCellKZGProofBatchFromBlobData([][]byte{}, [][]byte{}, [][]byte{}, 128)
+		require.NoError(t, err)
+	})
+
+	t.Run("mismatched blob and commitment count", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		err := VerifyCellKZGProofBatchFromBlobData(
+			[][]byte{blob[:]},
+			[][]byte{}, // Empty commitments
+			[][]byte{},
+			128,
+		)
+		require.ErrorContains(t, "expected 128 cell proofs", err)
+	})
+
+	t.Run("wrong cell proof count", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		// Wrong number of cell proofs - should be 128 for 1 blob, but provide 10
+		wrongCellProofs := make([][]byte, 10)
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, wrongCellProofs, numberOfColumns)
+		require.ErrorContains(t, "expected 128 cell proofs, got 10", err)
+	})
+
+	t.Run("invalid cell proofs should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		// Create invalid cell proofs (all zeros)
+		invalidCellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			invalidCellProofs[i] = make([]byte, 48) // All zeros
+		}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, invalidCellProofs, numberOfColumns)
+		require.ErrorContains(t, "cell batch verification", err)
+	})
+
+	t.Run("mismatched commitment should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Generate blob and correct cell proofs
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Generate wrong commitment from different blob
+		randBlob2 := random.GetRandBlob(456)
+		var differentBlob Blob
+		copy(differentBlob[:], randBlob2[:])
+		wrongCommitment, err := BlobToKZGCommitment(&differentBlob)
+		require.NoError(t, err)
+
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{wrongCommitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.ErrorContains(t, "cell KZG proof batch verification failed", err)
+	})
+
+	t.Run("invalid blob data that should cause ComputeCells to fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Create invalid blob (not properly formatted)
+		invalidBlobData := make([]byte, 10) // Too short
+		commitment := make([]byte, 48)      // Dummy commitment
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = make([]byte, 48)
+		}
+
+		blobs := [][]byte{invalidBlobData}
+		commitments := [][]byte{commitment}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.NotNil(t, err)
+		require.ErrorContains(t, "blobs len (10) differs from expected (131072)", err)
+	})
+
+	t.Run("invalid commitment size should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		// Create invalid commitment (wrong size)
+		invalidCommitment := make([]byte, 32) // Should be 48 bytes
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = make([]byte, 48)
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{invalidCommitment}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.ErrorContains(t, "commitments len (32) differs from expected (48)", err)
+	})
+
+	t.Run("invalid cell proof size should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		// Create invalid cell proofs (wrong size)
+		invalidCellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			if i == 0 {
+				invalidCellProofs[i] = make([]byte, 32) // Wrong size - should be 48
+			} else {
+				invalidCellProofs[i] = make([]byte, 48)
+			}
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, invalidCellProofs, numberOfColumns)
+		require.ErrorContains(t, "proofs len (32) differs from expected (48)", err)
+	})
+
+	t.Run("multiple blobs with mixed invalid commitments", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		// First blob - valid
+		randBlob1 := random.GetRandBlob(123)
+		var blob1 Blob
+		copy(blob1[:], randBlob1[:])
+		commitment1, err := BlobToKZGCommitment(&blob1)
+		require.NoError(t, err)
+		blobs[0] = blob1[:]
+		commitments[0] = commitment1[:]
+
+		// Second blob - use invalid commitment size
+		randBlob2 := random.GetRandBlob(456)
+		var blob2 Blob
+		copy(blob2[:], randBlob2[:])
+		blobs[1] = blob2[:]
+		commitments[1] = make([]byte, 32) // Wrong size
+
+		// Add cell proofs for both blobs
+		for i := 0; i < blobCount; i++ {
+			for j := uint64(0); j < numberOfColumns; j++ {
+				allCellProofs = append(allCellProofs, make([]byte, 48))
+			}
+		}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.ErrorContains(t, "commitments len (32) differs from expected (48)", err)
+	})
+
+	t.Run("multiple blobs with mixed invalid cell proof sizes", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		for i := 0; i < blobCount; i++ {
+			randBlob := random.GetRandBlob(int64(i))
+			var blob Blob
+			copy(blob[:], randBlob[:])
+			commitment, err := BlobToKZGCommitment(&blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+
+			// Add cell proofs - make some invalid in the second blob
+			for j := uint64(0); j < numberOfColumns; j++ {
+				if i == 1 && j == 64 {
+					// Invalid proof size in middle of second blob's proofs
+					allCellProofs = append(allCellProofs, make([]byte, 20))
+				} else {
+					allCellProofs = append(allCellProofs, make([]byte, 48))
+				}
+			}
+		}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.ErrorContains(t, "proofs len (20) differs from expected (48)", err)
+	})
+}

beacon-chain/blockchain/options.go

@@ -6,12 +6,11 @@ import (
 	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
-	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice"
+	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/slashings"
@@ -36,7 +35,7 @@ func WithMaxGoroutines(x int) Option {
 // WithLCStore for light client store access.
 func WithLCStore() Option {
 	return func(s *Service) error {
-		s.lcStore = lightclient.NewLightClientStore(s.cfg.BeaconDB)
+		s.lcStore = lightclient.NewLightClientStore(s.cfg.P2P, s.cfg.StateNotifier.StateFeed(), s.cfg.BeaconDB)
 		return nil
 	}
 }
@@ -235,14 +234,6 @@ func WithSyncChecker(checker Checker) Option {
 	}
 }
 
-// WithCustodyInfo sets the custody info for the blockchain service.
-func WithCustodyInfo(custodyInfo *peerdas.CustodyInfo) Option {
-	return func(s *Service) error {
-		s.cfg.CustodyInfo = custodyInfo
-		return nil
-	}
-}
-
 // WithSlasherEnabled sets whether the slasher is enabled or not.
 func WithSlasherEnabled(enabled bool) Option {
 	return func(s *Service) error {

beacon-chain/blockchain/process_block.go

@@ -3,7 +3,6 @@ package blockchain
 import (
 	"context"
 	"fmt"
-	"slices"
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
@@ -159,7 +158,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	}
 
 	// Fill in missing blocks
-	if err := s.fillInForkChoiceMissingBlocks(ctx, blks[0], preState.CurrentJustifiedCheckpoint(), preState.FinalizedCheckpoint()); err != nil {
+	if err := s.fillInForkChoiceMissingBlocks(ctx, blks[0], preState.FinalizedCheckpoint(), preState.CurrentJustifiedCheckpoint()); err != nil {
 		return errors.Wrap(err, "could not fill in missing blocks to forkchoice")
 	}
 
@@ -240,13 +239,14 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 			}
 		}
 
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
-			return errors.Wrapf(err, "could not validate sidecar availability at slot %d", b.Block().Slot())
+		if err := s.areSidecarsAvailable(ctx, avs, b); err != nil {
+			return errors.Wrapf(err, "could not validate sidecar availability for block %#x at slot %d", b.Root(), b.Block().Slot())
 		}
+
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b,
 			JustifiedCheckpoint: jCheckpoints[i],
 			FinalizedCheckpoint: fCheckpoints[i]}
-		pendingNodes[len(blks)-i-1] = args
+		pendingNodes[i] = args
 		if err := s.saveInitSyncBlock(ctx, root, b); err != nil {
 			tracing.AnnotateError(span, err)
 			return err
@@ -283,14 +283,10 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	if err := s.cfg.StateGen.SaveState(ctx, lastBR, preState); err != nil {
 		return err
 	}
-	// Insert all nodes but the last one to forkchoice
+	// Insert all nodes to forkchoice
 	if err := s.cfg.ForkChoiceStore.InsertChain(ctx, pendingNodes); err != nil {
 		return errors.Wrap(err, "could not insert batch to forkchoice")
 	}
-	// Insert the last block to forkchoice
-	if err := s.cfg.ForkChoiceStore.InsertNode(ctx, preState, lastB); err != nil {
-		return errors.Wrap(err, "could not insert last block in batch to forkchoice")
-	}
 	// Set their optimistic status
 	if isValidPayload {
 		if err := s.cfg.ForkChoiceStore.SetOptimisticToValid(ctx, lastBR); err != nil {
@@ -308,6 +304,30 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }
 
+func (s *Service) areSidecarsAvailable(ctx context.Context, avs das.AvailabilityStore, roBlock consensusblocks.ROBlock) error {
+	blockVersion := roBlock.Version()
+	block := roBlock.Block()
+	slot := block.Slot()
+
+	if blockVersion >= version.Fulu {
+		if err := s.areDataColumnsAvailable(ctx, roBlock.Root(), block); err != nil {
+			return errors.Wrapf(err, "are data columns available for block %#x with slot %d", roBlock.Root(), slot)
+		}
+
+		return nil
+	}
+
+	if blockVersion >= version.Deneb {
+		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), roBlock); err != nil {
+			return errors.Wrapf(err, "could not validate sidecar availability at slot %d", slot)
+		}
+
+		return nil
+	}
+
+	return nil
+}
+
 func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.BeaconState) error {
 	e := coreTime.CurrentEpoch(st)
 	if err := helpers.UpdateCommitteeCache(ctx, st, e); err != nil {
@@ -584,7 +604,7 @@ func (s *Service) runLateBlockTasks() {
 // It returns a map where each key represents a missing BlobSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // BlobSidecars against the set of known missing sidecars.
-func missingBlobIndices(bs *filesystem.BlobStorage, root [fieldparams.RootLength]byte, expected [][]byte, slot primitives.Slot) (map[uint64]bool, error) {
+func missingBlobIndices(store *filesystem.BlobStorage, root [fieldparams.RootLength]byte, expected [][]byte, slot primitives.Slot) (map[uint64]bool, error) {
 	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	if len(expected) == 0 {
 		return nil, nil
@@ -592,7 +612,7 @@ func missingBlobIndices(bs *filesystem.BlobStorage, root [fieldparams.RootLength
 	if len(expected) > maxBlobsPerBlock {
 		return nil, errMaxBlobsExceeded
 	}
-	indices := bs.Summary(root)
+	indices := store.Summary(root)
 	missing := make(map[uint64]bool, len(expected))
 	for i := range expected {
 		if len(expected[i]) > 0 && !indices.HasIndex(uint64(i)) {
@@ -607,7 +627,7 @@ func missingBlobIndices(bs *filesystem.BlobStorage, root [fieldparams.RootLength
 // It returns a map where each key represents a missing DataColumnSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // DataColumns against the set of known missing sidecars.
-func missingDataColumnIndices(bs *filesystem.DataColumnStorage, root [fieldparams.RootLength]byte, expected map[uint64]bool) (map[uint64]bool, error) {
+func missingDataColumnIndices(store *filesystem.DataColumnStorage, root [fieldparams.RootLength]byte, expected map[uint64]bool) (map[uint64]bool, error) {
 	if len(expected) == 0 {
 		return nil, nil
 	}
@@ -619,7 +639,7 @@ func missingDataColumnIndices(bs *filesystem.DataColumnStorage, root [fieldparam
 	}
 
 	// Get a summary of the data columns stored in the database.
-	summary := bs.Summary(root)
+	summary := store.Summary(root)
 
 	// Check all expected data columns against the summary.
 	missing := make(map[uint64]bool)
@@ -639,14 +659,14 @@ func missingDataColumnIndices(bs *filesystem.DataColumnStorage, root [fieldparam
 // closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
 func (s *Service) isDataAvailable(
 	ctx context.Context,
-	root [fieldparams.RootLength]byte,
-	signedBlock interfaces.ReadOnlySignedBeaconBlock,
+	roBlock consensusblocks.ROBlock,
 ) error {
-	block := signedBlock.Block()
+	block := roBlock.Block()
 	if block == nil {
 		return errors.New("invalid nil beacon block")
 	}
 
+	root := roBlock.Root()
 	blockVersion := block.Version()
 	if blockVersion >= version.Fulu {
 		return s.areDataColumnsAvailable(ctx, root, block)
@@ -666,10 +686,9 @@ func (s *Service) areDataColumnsAvailable(
 	root [fieldparams.RootLength]byte,
 	block interfaces.ReadOnlyBeaconBlock,
 ) error {
-	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS
 	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
 	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
-
 	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
 		return nil
 	}
@@ -690,16 +709,21 @@ func (s *Service) areDataColumnsAvailable(
 	}
 
 	// All columns to sample need to be available for the block to be considered available.
-	// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/das-core.md#custody-sampling
 	nodeID := s.cfg.P2P.NodeID()
 
-	// Prevent custody group count to change during the rest of the function.
-	s.cfg.CustodyInfo.Mut.RLock()
-	defer s.cfg.CustodyInfo.Mut.RUnlock()
-
 	// Get the custody group sampling size for the node.
-	custodyGroupSamplingSize := s.cfg.CustodyInfo.CustodyGroupSamplingSize(peerdas.Actual)
-	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupSamplingSize)
+	custodyGroupCount, err := s.cfg.P2P.CustodyGroupCount()
+	if err != nil {
+		return errors.Wrap(err, "custody group count")
+	}
+
+	// Compute the sampling size.
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#custody-sampling
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+	samplingSize := max(samplesPerSlot, custodyGroupCount)
+
+	// Get the peer info for the node.
+	peerInfo, _, err := peerdas.Info(nodeID, samplingSize)
 	if err != nil {
 		return errors.Wrap(err, "peer info")
 	}
@@ -712,7 +736,7 @@ func (s *Service) areDataColumnsAvailable(
 	summary := s.dataColumnStorage.Summary(root)
 	storedDataColumnsCount := summary.Count()
 
-	minimumColumnCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+	minimumColumnCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
 
 	// As soon as we have enough data column sidecars, we can reconstruct the missing ones.
 	// We don't need to wait for the rest of the data columns to declare the block as available.
@@ -721,14 +745,14 @@ func (s *Service) areDataColumnsAvailable(
 	}
 
 	// Get a map of data column indices that are not currently available.
-	missingMap, err := missingDataColumnIndices(s.dataColumnStorage, root, peerInfo.CustodyColumns)
+	missing, err := missingDataColumnIndices(s.dataColumnStorage, root, peerInfo.CustodyColumns)
 	if err != nil {
 		return errors.Wrap(err, "missing data columns")
 	}
 
 	// If there are no missing indices, all data column sidecars are available.
 	// This is the happy path.
-	if len(missingMap) == 0 {
+	if len(missing) == 0 {
 		return nil
 	}
 
@@ -745,33 +769,17 @@ func (s *Service) areDataColumnsAvailable(
 	// Avoid logging if DA check is called after next slot start.
 	if nextSlot.After(time.Now()) {
 		timer := time.AfterFunc(time.Until(nextSlot), func() {
-			missingMapCount := uint64(len(missingMap))
+			missingCount := uint64(len(missing))
 
-			if missingMapCount == 0 {
+			if missingCount == 0 {
 				return
 			}
 
-			var (
-				expected interface{} = "all"
-				missing  interface{} = "all"
-			)
-
-			numberOfColumns := params.BeaconConfig().NumberOfColumns
-			colMapCount := uint64(len(peerInfo.CustodyColumns))
-
-			if colMapCount < numberOfColumns {
-				expected = uint64MapToSortedSlice(peerInfo.CustodyColumns)
-			}
-
-			if missingMapCount < numberOfColumns {
-				missing = uint64MapToSortedSlice(missingMap)
-			}
-
 			log.WithFields(logrus.Fields{
 				"slot":            block.Slot(),
 				"root":            fmt.Sprintf("%#x", root),
-				"columnsExpected": expected,
-				"columnsWaiting":  missing,
+				"columnsExpected": helpers.SortedPrettySliceFromMap(peerInfo.CustodyColumns),
+				"columnsWaiting":  helpers.SortedPrettySliceFromMap(missing),
 			}).Warning("Data columns still missing at slot end")
 		})
 		defer timer.Stop()
@@ -787,7 +795,7 @@ func (s *Service) areDataColumnsAvailable(
 
 			for _, index := range idents.Indices {
 				// This is a data column we are expecting.
-				if _, ok := missingMap[index]; ok {
+				if _, ok := missing[index]; ok {
 					storedDataColumnsCount++
 				}
 
@@ -798,10 +806,10 @@ func (s *Service) areDataColumnsAvailable(
 				}
 
 				// Remove the index from the missing map.
-				delete(missingMap, index)
+				delete(missing, index)
 
 				// Return if there is no more missing data columns.
-				if len(missingMap) == 0 {
+				if len(missing) == 0 {
 					return nil
 				}
 			}
@@ -809,13 +817,13 @@ func (s *Service) areDataColumnsAvailable(
 		case <-ctx.Done():
 			var missingIndices interface{} = "all"
 			numberOfColumns := params.BeaconConfig().NumberOfColumns
-			missingIndicesCount := uint64(len(missingMap))
+			missingIndicesCount := uint64(len(missing))
 
 			if missingIndicesCount < numberOfColumns {
-				missingIndices = uint64MapToSortedSlice(missingMap)
+				missingIndices = helpers.SortedPrettySliceFromMap(missing)
 			}
 
-			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing %v", block.Slot(), root, missingIndices)
+			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing: %v", block.Slot(), root, missingIndices)
 		}
 	}
 }
@@ -896,16 +904,6 @@ func (s *Service) areBlobsAvailable(ctx context.Context, root [fieldparams.RootL
 	}
 }
 
-// uint64MapToSortedSlice produces a sorted uint64 slice from a map.
-func uint64MapToSortedSlice(input map[uint64]bool) []uint64 {
-	output := make([]uint64, 0, len(input))
-	for idx := range input {
-		output = append(output, idx)
-	}
-	slices.Sort[[]uint64](output)
-	return output
-}
-
 // lateBlockTasks  is called 4 seconds into the slot and performs tasks
 // related to late blocks. It emits a MissedSlot state feed event.
 // It calls FCU and sets the right attributes if we are proposing next slot

beacon-chain/blockchain/process_block_helpers.go

@@ -1,17 +1,14 @@
 package blockchain
 
 import (
-	"bytes"
 	"context"
 	"fmt"
-	"strings"
+	"slices"
 	"time"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
-	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
@@ -31,6 +28,10 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// ErrInvalidCheckpointArgs may be returned when the finalized checkpoint has an epoch greater than the justified checkpoint epoch.
+// If you are seeing this error, make sure you haven't mixed up the order of the arguments in the method you are calling.
+var ErrInvalidCheckpointArgs = errors.New("finalized checkpoint cannot be greater than justified checkpoint")
+
 // CurrentSlot returns the current slot based on time.
 func (s *Service) CurrentSlot() primitives.Slot {
 	return slots.CurrentSlot(s.genesisTime)
@@ -130,38 +131,26 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 	})
 }
 
+// processLightClientUpdates saves the light client data in lcStore, when feature flag is enabled.
 func (s *Service) processLightClientUpdates(cfg *postBlockProcessConfig) {
-	if err := s.processLightClientUpdate(cfg); err != nil {
-		log.WithError(err).Error("Failed to process light client update")
-	}
-	if err := s.processLightClientBootstrap(cfg); err != nil {
-		log.WithError(err).Error("Failed to process light client bootstrap")
-	}
-	if err := s.processLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
-		log.WithError(err).Error("Failed to process light client optimistic update")
-	}
-	if err := s.processLightClientFinalityUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
-		log.WithError(err).Error("Failed to process light client finality update")
-	}
-}
-
-// processLightClientUpdate saves the light client update for this block
-// if it's better than the already saved one, when feature flag is enabled.
-func (s *Service) processLightClientUpdate(cfg *postBlockProcessConfig) error {
 	attestedRoot := cfg.roblock.Block().ParentRoot()
 	attestedBlock, err := s.getBlock(cfg.ctx, attestedRoot)
 	if err != nil {
-		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
+		log.WithError(err).Error("processLightClientUpdates: Could not get attested block")
+		return
 	}
 	if attestedBlock == nil || attestedBlock.IsNil() {
-		return errors.New("attested block is nil")
+		log.Error("processLightClientUpdates: Could not get attested block")
+		return
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(cfg.ctx, attestedRoot)
 	if err != nil {
-		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
+		log.WithError(err).Error("processLightClientUpdates: Could not get attested state")
+		return
 	}
 	if attestedState == nil || attestedState.IsNil() {
-		return errors.New("attested state is nil")
+		log.Error("processLightClientUpdates: Could not get attested state")
+		return
 	}
 
 	finalizedRoot := attestedState.FinalizedCheckpoint().Root
@@ -169,201 +158,17 @@ func (s *Service) processLightClientUpdate(cfg *postBlockProcessConfig) error {
 	if err != nil {
 		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
 			log.Debugf("Skipping saving light client update because finalized block is nil for root %#x", finalizedRoot)
-			return nil
+			return
 		}
-		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
+		log.WithError(err).Error("processLightClientUpdates: Could not get finalized block")
+		return
 	}
 
-	update, err := lightclient.NewLightClientUpdateFromBeaconState(
-		cfg.ctx,
-		s.CurrentSlot(),
-		cfg.postState,
-		cfg.roblock,
-		attestedState,
-		attestedBlock,
-		finalizedBlock,
-	)
+	err = s.lcStore.SaveLCData(cfg.ctx, cfg.postState, cfg.roblock, attestedState, attestedBlock, finalizedBlock, s.headRoot())
 	if err != nil {
-		return errors.Wrapf(err, "could not create light client update")
+		log.WithError(err).Error("processLightClientUpdates: Could not save light client data")
 	}
-
-	period := slots.SyncCommitteePeriod(slots.ToEpoch(attestedState.Slot()))
-
-	oldUpdate, err := s.cfg.BeaconDB.LightClientUpdate(cfg.ctx, period)
-	if err != nil {
-		return errors.Wrapf(err, "could not get current light client update")
-	}
-
-	if oldUpdate == nil {
-		if err := s.cfg.BeaconDB.SaveLightClientUpdate(cfg.ctx, period, update); err != nil {
-			return errors.Wrapf(err, "could not save light client update")
-		}
-		log.WithField("period", period).Debug("Saved new light client update")
-		return nil
-	}
-
-	isNewUpdateBetter, err := lightclient.IsBetterUpdate(update, oldUpdate)
-	if err != nil {
-		return errors.Wrapf(err, "could not compare light client updates")
-	}
-
-	if isNewUpdateBetter {
-		if err := s.cfg.BeaconDB.SaveLightClientUpdate(cfg.ctx, period, update); err != nil {
-			return errors.Wrapf(err, "could not save light client update")
-		}
-		log.WithField("period", period).Debug("Saved new light client update")
-		return nil
-	}
-	log.WithField("period", period).Debug("New light client update is not better than the current one, skipping save")
-	return nil
-}
-
-// processLightClientBootstrap saves a light client bootstrap for this block
-// when feature flag is enabled.
-func (s *Service) processLightClientBootstrap(cfg *postBlockProcessConfig) error {
-	blockRoot := cfg.roblock.Root()
-	bootstrap, err := lightclient.NewLightClientBootstrapFromBeaconState(cfg.ctx, s.CurrentSlot(), cfg.postState, cfg.roblock)
-	if err != nil {
-		return errors.Wrapf(err, "could not create light client bootstrap")
-	}
-	if err := s.lcStore.SaveLightClientBootstrap(cfg.ctx, blockRoot, bootstrap); err != nil {
-		return errors.Wrapf(err, "could not save light client bootstrap")
-	}
-	return nil
-}
-
-func (s *Service) processLightClientFinalityUpdate(
-	ctx context.Context,
-	signed interfaces.ReadOnlySignedBeaconBlock,
-	postState state.BeaconState,
-) error {
-	attestedRoot := signed.Block().ParentRoot()
-	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
-	if err != nil {
-		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
-	}
-	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
-	if err != nil {
-		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
-	}
-
-	finalizedCheckpoint := attestedState.FinalizedCheckpoint()
-
-	// Check if the finalized checkpoint has changed
-	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
-		return nil
-	}
-
-	finalizedRoot := bytesutil.ToBytes32(finalizedCheckpoint.Root)
-	finalizedBlock, err := s.cfg.BeaconDB.Block(ctx, finalizedRoot)
-	if err != nil {
-		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
-			log.Debugf("Skipping processing light client finality update: Finalized block is nil for root %#x", finalizedRoot)
-			return nil
-		}
-		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
-	}
-
-	newUpdate, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
-		ctx,
-		postState.Slot(),
-		postState,
-		signed,
-		attestedState,
-		attestedBlock,
-		finalizedBlock,
-	)
-
-	if err != nil {
-		return errors.Wrap(err, "could not create light client finality update")
-	}
-
-	lastUpdate := s.lcStore.LastFinalityUpdate()
-	if lastUpdate != nil {
-		// The finalized_header.beacon.lastUpdateSlot is greater than that of all previously forwarded finality_updates,
-		// or it matches the highest previously forwarded lastUpdateSlot and also has a sync_aggregate indicating supermajority (> 2/3)
-		// sync committee participation while the previously forwarded finality_update for that lastUpdateSlot did not indicate supermajority
-		newUpdateSlot := newUpdate.FinalizedHeader().Beacon().Slot
-		newHasSupermajority := lightclient.UpdateHasSupermajority(newUpdate.SyncAggregate())
-
-		lastUpdateSlot := lastUpdate.FinalizedHeader().Beacon().Slot
-		lastHasSupermajority := lightclient.UpdateHasSupermajority(lastUpdate.SyncAggregate())
-
-		if newUpdateSlot < lastUpdateSlot {
-			log.Debug("Skip saving light client finality newUpdate: Older than local newUpdate")
-			return nil
-		}
-		if newUpdateSlot == lastUpdateSlot && (lastHasSupermajority || !newHasSupermajority) {
-			log.Debug("Skip saving light client finality update: No supermajority advantage")
-			return nil
-		}
-	}
-	log.Debug("Saving new light client finality update")
-	s.lcStore.SetLastFinalityUpdate(newUpdate)
-
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientFinalityUpdate,
-		Data: newUpdate,
-	})
-
-	if err = s.cfg.P2P.BroadcastLightClientFinalityUpdate(ctx, newUpdate); err != nil {
-		return errors.Wrap(err, "could not broadcast light client finality update")
-	}
-
-	return nil
-}
-
-func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
-	postState state.BeaconState) error {
-	attestedRoot := signed.Block().ParentRoot()
-	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
-	if err != nil {
-		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
-	}
-	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
-	if err != nil {
-		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
-	}
-
-	newUpdate, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
-		ctx,
-		postState.Slot(),
-		postState,
-		signed,
-		attestedState,
-		attestedBlock,
-	)
-
-	if err != nil {
-		if strings.Contains(err.Error(), lightclient.ErrNotEnoughSyncCommitteeBits) {
-			log.WithError(err).Debug("Skipping processing light client optimistic update")
-			return nil
-		}
-		return errors.Wrap(err, "could not create light client optimistic update")
-	}
-
-	lastUpdate := s.lcStore.LastOptimisticUpdate()
-	if lastUpdate != nil {
-		// The attested_header.beacon.slot is greater than that of all previously forwarded optimistic updates
-		if newUpdate.AttestedHeader().Beacon().Slot <= lastUpdate.AttestedHeader().Beacon().Slot {
-			log.Debug("Skip saving light client optimistic update: Older than local update")
-			return nil
-		}
-	}
-
-	log.Debug("Saving new light client optimistic update")
-	s.lcStore.SetLastOptimisticUpdate(newUpdate)
-
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientOptimisticUpdate,
-		Data: newUpdate,
-	})
-
-	if err = s.cfg.P2P.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
-		return errors.Wrap(err, "could not broadcast light client optimistic update")
-	}
-
-	return nil
+	log.Debug("Processed light client updates")
 }
 
 // updateCachesPostBlockProcessing updates the next slot cache and handles the epoch
@@ -561,6 +366,9 @@ func (s *Service) ancestorByDB(ctx context.Context, r [32]byte, slot primitives.
 // This is useful for block tree visualizer and additional vote accounting.
 func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
 	fCheckpoint, jCheckpoint *ethpb.Checkpoint) error {
+	if fCheckpoint.Epoch > jCheckpoint.Epoch {
+		return ErrInvalidCheckpointArgs
+	}
 	pendingNodes := make([]*forkchoicetypes.BlockAndCheckpoints, 0)
 
 	// Fork choice only matters from last finalized slot.
@@ -569,15 +377,8 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, signed inte
 	if err != nil {
 		return err
 	}
-	// The first block can have a bogus root since the block is not inserted in forkchoice
-	roblock, err := consensus_blocks.NewROBlockWithRoot(signed, [32]byte{})
-	if err != nil {
-		return err
-	}
-	pendingNodes = append(pendingNodes, &forkchoicetypes.BlockAndCheckpoints{Block: roblock,
-		JustifiedCheckpoint: jCheckpoint, FinalizedCheckpoint: fCheckpoint})
+	root := signed.Block().ParentRoot()
 	// As long as parent node is not in fork choice store, and parent node is in DB.
-	root := roblock.Block().ParentRoot()
 	for !s.cfg.ForkChoiceStore.HasNode(root) && s.cfg.BeaconDB.HasBlock(ctx, root) {
 		b, err := s.getBlock(ctx, root)
 		if err != nil {
@@ -596,12 +397,13 @@ func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, signed inte
 			FinalizedCheckpoint: fCheckpoint}
 		pendingNodes = append(pendingNodes, args)
 	}
-	if len(pendingNodes) == 1 {
+	if len(pendingNodes) == 0 {
 		return nil
 	}
 	if root != s.ensureRootNotZeros(finalized.Root) && !s.cfg.ForkChoiceStore.HasNode(root) {
 		return ErrNotDescendantOfFinalized
 	}
+	slices.Reverse(pendingNodes)
 	return s.cfg.ForkChoiceStore.InsertChain(ctx, pendingNodes)
 }
 

beacon-chain/blockchain/receive_attestation.go

@@ -177,7 +177,7 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 	for _, a := range atts {
 		// Based on the spec, don't process the attestation until the subsequent slot.
 		// This delays consideration in the fork choice until their slot is in the past.
-		// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/fork-choice.md#validate_on_attestation
+		// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/fork-choice.md#validate_on_attestation
 		nextSlot := a.GetData().Slot + 1
 		if err := slots.VerifyTime(s.genesisTime, nextSlot, disparity); err != nil {
 			continue

beacon-chain/blockchain/receive_block.go

@@ -16,7 +16,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/slasher/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/features"
-	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -84,12 +83,16 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	}
 
 	receivedTime := time.Now()
-	s.blockBeingSynced.set(blockRoot)
+	err := s.blockBeingSynced.set(blockRoot)
+	if errors.Is(err, errBlockBeingSynced) {
+		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring block currently being synced")
+		return nil
+	}
 	defer s.blockBeingSynced.unset(blockRoot)
 
 	blockCopy, err := block.Copy()
 	if err != nil {
-		return err
+		return errors.Wrap(err, "block copy")
 	}
 
 	preState, err := s.getBlockPreState(ctx, blockCopy.Block())
@@ -100,17 +103,17 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	currentCheckpoints := s.saveCurrentCheckpoints(preState)
 	roblock, err := blocks.NewROBlockWithRoot(blockCopy, blockRoot)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "new ro block with root")
 	}
 
 	postState, isValidPayload, err := s.validateExecutionAndConsensus(ctx, preState, roblock)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "validator execution and consensus")
 	}
 
-	daWaitedTime, err := s.handleDA(ctx, blockCopy, blockRoot, avs)
+	daWaitedTime, err := s.handleDA(ctx, avs, roblock)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "handle da")
 	}
 
 	// Defragment the state before continuing block processing.
@@ -131,10 +134,10 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err := s.postBlockProcess(args); err != nil {
 		err := errors.Wrap(err, "could not process block")
 		tracing.AnnotateError(span, err)
-		return err
+		return errors.Wrap(err, "post block process")
 	}
 	if err := s.updateCheckpoints(ctx, currentCheckpoints, preState, postState, blockRoot); err != nil {
-		return err
+		return errors.Wrap(err, "update checkpoints")
 	}
 	// If slasher is configured, forward the attestations in the block via an event feed for processing.
 	if s.slasherEnabled {
@@ -148,12 +151,12 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 
 	// Have we been finalizing? Should we start saving hot states to db?
 	if err := s.checkSaveHotStateDB(ctx); err != nil {
-		return err
+		return errors.Wrap(err, "check save hot state db")
 	}
 
 	// We apply the same heuristic to some of our more important caches.
 	if err := s.handleCaches(); err != nil {
-		return err
+		return errors.Wrap(err, "handle caches")
 	}
 	s.reportPostBlockProcessing(blockCopy, blockRoot, receivedTime, daWaitedTime)
 	return nil
@@ -236,37 +239,19 @@ func (s *Service) validateExecutionAndConsensus(
 	return postState, isValidPayload, nil
 }
 
-func (s *Service) handleDA(
-	ctx context.Context,
-	block interfaces.SignedBeaconBlock,
-	blockRoot [fieldparams.RootLength]byte,
-	avs das.AvailabilityStore,
-) (elapsed time.Duration, err error) {
-	defer func(start time.Time) {
-		elapsed = time.Since(start)
-
-		if err == nil {
-			dataAvailWaitedTime.Observe(float64(elapsed.Milliseconds()))
-		}
-	}(time.Now())
-
-	if avs == nil {
-		if err = s.isDataAvailable(ctx, blockRoot, block); err != nil {
-			return
-		}
-
-		return
+func (s *Service) handleDA(ctx context.Context, avs das.AvailabilityStore, block blocks.ROBlock) (time.Duration, error) {
+	var err error
+	start := time.Now()
+	if avs != nil {
+		err = avs.IsDataAvailable(ctx, s.CurrentSlot(), block)
+	} else {
+		err = s.isDataAvailable(ctx, block)
 	}
-
-	var rob blocks.ROBlock
-	rob, err = blocks.NewROBlockWithRoot(block, blockRoot)
-	if err != nil {
-		return
+	elapsed := time.Since(start)
+	if err == nil {
+		dataAvailWaitedTime.Observe(float64(elapsed.Milliseconds()))
 	}
-
-	err = avs.IsDataAvailable(ctx, s.CurrentSlot(), rob)
-
-	return
+	return elapsed, err
 }
 
 func (s *Service) reportPostBlockProcessing(
@@ -300,15 +285,45 @@ func (s *Service) reportPostBlockProcessing(
 
 func (s *Service) executePostFinalizationTasks(ctx context.Context, finalizedState state.BeaconState) {
 	finalized := s.cfg.ForkChoiceStore.FinalizedCheckpoint()
+
+	// Send finalization event
 	go func() {
 		s.sendNewFinalizedEvent(ctx, finalizedState)
 	}()
 
+	// Insert finalized deposits into finalized deposit trie
 	depCtx, cancel := context.WithTimeout(context.Background(), depositDeadline)
 	go func() {
 		s.insertFinalizedDepositsAndPrune(depCtx, finalized.Root)
 		cancel()
 	}()
+
+	if features.Get().EnableLightClient {
+		// Save a light client bootstrap for the finalized checkpoint
+		go func() {
+			st, err := s.cfg.StateGen.StateByRoot(ctx, finalized.Root)
+			if err != nil {
+				log.WithError(err).Error("Could not retrieve state for finalized root to save light client bootstrap")
+				return
+			}
+			err = s.lcStore.SaveLightClientBootstrap(s.ctx, finalized.Root, st)
+			if err != nil {
+				log.WithError(err).Error("Could not save light client bootstrap by block root")
+			} else {
+				log.Debugf("Saved light client bootstrap for finalized root %#x", finalized.Root)
+			}
+		}()
+
+		// Clean up the light client store caches
+		go func() {
+			err := s.lcStore.MigrateToCold(s.ctx, finalized.Root)
+			if err != nil {
+				log.WithError(err).Error("Could not migrate light client store to cold storage")
+			} else {
+				log.Debugf("Migrated light client store to cold storage for finalized root %#x", finalized.Root)
+			}
+		}()
+	}
 }
 
 // ReceiveBlockBatch processes the whole block batch at once, assuming the block batch is linear ,transitioning

beacon-chain/blockchain/receive_block_test.go

@@ -10,6 +10,8 @@ import (
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
+	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
+	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/voluntaryexits"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -19,6 +21,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	ethpbv1 "github.com/OffchainLabs/prysm/v6/proto/eth/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -189,7 +192,9 @@ func TestHandleDA(t *testing.T) {
 	require.NoError(t, err)
 
 	s, _ := minimalTestService(t)
-	elapsed, err := s.handleDA(t.Context(), signedBeaconBlock, [fieldparams.RootLength]byte{}, nil)
+	block, err := blocks.NewROBlockWithRoot(signedBeaconBlock, [32]byte{})
+	require.NoError(t, err)
+	elapsed, err := s.handleDA(t.Context(), nil, block)
 	require.NoError(t, err)
 	require.Equal(t, true, elapsed > 0, "Elapsed time should be greater than 0")
 }
@@ -308,7 +313,10 @@ func TestService_HasBlock(t *testing.T) {
 	r, err = b.Block.HashTreeRoot()
 	require.NoError(t, err)
 	require.Equal(t, true, s.HasBlock(t.Context(), r))
-	s.blockBeingSynced.set(r)
+	err = s.blockBeingSynced.set(r)
+	require.NoError(t, err)
+	err = s.blockBeingSynced.set(r)
+	require.ErrorIs(t, err, errBlockBeingSynced)
 	require.Equal(t, false, s.HasBlock(t.Context(), r))
 }
 
@@ -564,3 +572,44 @@ func Test_executePostFinalizationTasks(t *testing.T) {
 	})
 
 }
+
+func TestProcessLightClientBootstrap(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+	defer reset()
+
+	s, tr := minimalTestService(t, WithLCStore())
+	ctx := tr.ctx
+
+	for testVersion := version.Altair; testVersion <= version.Electra; testVersion++ {
+		t.Run(version.String(testVersion), func(t *testing.T) {
+			l := util.NewTestLightClient(t, testVersion)
+
+			require.NoError(t, s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock))
+			finalizedBlockRoot, err := l.FinalizedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			require.NoError(t, s.cfg.BeaconDB.SaveState(ctx, l.FinalizedState, finalizedBlockRoot))
+
+			cp := l.AttestedState.FinalizedCheckpoint()
+			require.DeepSSZEqual(t, finalizedBlockRoot, [32]byte(cp.Root))
+
+			require.NoError(t, s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: cp.Epoch, Root: [32]byte(cp.Root)}))
+
+			s.executePostFinalizationTasks(s.ctx, l.AttestedState)
+
+			// wait for the goroutine to finish processing
+			time.Sleep(1 * time.Second)
+
+			// Check that the light client bootstrap is saved
+			b, err := s.lcStore.LightClientBootstrap(ctx, [32]byte(cp.Root))
+			require.NoError(t, err)
+			require.NotNil(t, b)
+
+			btst, err := lightClient.NewLightClientBootstrapFromBeaconState(ctx, l.FinalizedState.Slot(), l.FinalizedState, l.FinalizedBlock)
+			require.NoError(t, err)
+			require.DeepEqual(t, btst, b)
+			require.Equal(t, b.Version(), testVersion)
+		})
+	}
+}

beacon-chain/blockchain/receive_data_column.go

@@ -15,10 +15,9 @@ func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataC
 }
 
 // ReceiveDataColumn receives a single data column.
-// (It is only a wrapper around ReceiveDataColumns.)
 func (s *Service) ReceiveDataColumn(dataColumnSidecar blocks.VerifiedRODataColumn) error {
 	if err := s.dataColumnStorage.Save([]blocks.VerifiedRODataColumn{dataColumnSidecar}); err != nil {
-		return errors.Wrap(err, "save data column sidecars")
+		return errors.Wrap(err, "save data column sidecar")
 	}
 
 	return nil

beacon-chain/blockchain/service.go

@@ -12,17 +12,15 @@ import (
 	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
-	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
 	f "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice"
+	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/slashings"
@@ -31,6 +29,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -97,7 +96,6 @@ type config struct {
 	FinalizedStateAtStartUp state.BeaconState
 	ExecutionEngineCaller   execution.EngineCaller
 	SyncChecker             Checker
-	CustodyInfo             *peerdas.CustodyInfo
 }
 
 // Checker is an interface used to determine if a node is in initial sync
@@ -208,17 +206,9 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 
 // Start a blockchain service's main event loop.
 func (s *Service) Start() {
-	saved := s.cfg.FinalizedStateAtStartUp
 	defer s.removeStartupState()
-
-	if saved != nil && !saved.IsNil() {
-		if err := s.StartFromSavedState(saved); err != nil {
-			log.Fatal(err)
-		}
-	} else {
-		if err := s.startFromExecutionChain(); err != nil {
-			log.Fatal(err)
-		}
+	if err := s.StartFromSavedState(s.cfg.FinalizedStateAtStartUp); err != nil {
+		log.Fatal(err)
 	}
 	s.spawnProcessAttestationsRoutine()
 	go s.runLateBlockTasks()
@@ -267,6 +257,9 @@ func (s *Service) Status() error {
 
 // StartFromSavedState initializes the blockchain using a previously saved finalized checkpoint.
 func (s *Service) StartFromSavedState(saved state.BeaconState) error {
+	if state.IsNil(saved) {
+		return errors.New("Last finalized state at startup is nil")
+	}
 	log.Info("Blockchain data already exists in DB, initializing...")
 	s.genesisTime = saved.GenesisTime()
 	s.cfg.AttService.SetGenesisTime(saved.GenesisTime())
@@ -296,6 +289,20 @@ func (s *Service) StartFromSavedState(saved state.BeaconState) error {
 	if err := s.clockSetter.SetClock(startup.NewClock(s.genesisTime, vr)); err != nil {
 		return errors.Wrap(err, "failed to initialize blockchain service")
 	}
+
+	if !params.FuluEnabled() {
+		return nil
+	}
+
+	earliestAvailableSlot, custodySubnetCount, err := s.updateCustodyInfoInDB(saved.Slot())
+	if err != nil {
+		return errors.Wrap(err, "could not get and save custody group count")
+	}
+
+	if _, _, err := s.cfg.P2P.UpdateCustodyInfo(earliestAvailableSlot, custodySubnetCount); err != nil {
+		return errors.Wrap(err, "update custody info")
+	}
+
 	return nil
 }
 
@@ -358,62 +365,6 @@ func (s *Service) initializeHead(ctx context.Context, st state.BeaconState) erro
 	return nil
 }
 
-func (s *Service) startFromExecutionChain() error {
-	log.Info("Waiting to reach the validator deposit threshold to start the beacon chain...")
-	if s.cfg.ChainStartFetcher == nil {
-		return errors.New("not configured execution chain")
-	}
-	go func() {
-		stateChannel := make(chan *feed.Event, 1)
-		stateSub := s.cfg.StateNotifier.StateFeed().Subscribe(stateChannel)
-		defer stateSub.Unsubscribe()
-		for {
-			select {
-			case e := <-stateChannel:
-				if e.Type == statefeed.ChainStarted {
-					data, ok := e.Data.(*statefeed.ChainStartedData)
-					if !ok {
-						log.Error("Event data is not type *statefeed.ChainStartedData")
-						return
-					}
-					log.WithField("startTime", data.StartTime).Debug("Received chain start event")
-					s.onExecutionChainStart(s.ctx, data.StartTime)
-					return
-				}
-			case <-s.ctx.Done():
-				log.Debug("Context closed, exiting goroutine")
-				return
-			case err := <-stateSub.Err():
-				log.WithError(err).Error("Subscription to state forRoot failed")
-				return
-			}
-		}
-	}()
-
-	return nil
-}
-
-// onExecutionChainStart initializes a series of deposits from the ChainStart deposits in the eth1
-// deposit contract, initializes the beacon chain's state, and kicks off the beacon chain.
-func (s *Service) onExecutionChainStart(ctx context.Context, genesisTime time.Time) {
-	preGenesisState := s.cfg.ChainStartFetcher.PreGenesisState()
-	initializedState, err := s.initializeBeaconChain(ctx, genesisTime, preGenesisState, s.cfg.ChainStartFetcher.ChainStartEth1Data())
-	if err != nil {
-		log.WithError(err).Fatal("Could not initialize beacon chain")
-	}
-	// We start a counter to genesis, if needed.
-	gRoot, err := initializedState.HashTreeRoot(s.ctx)
-	if err != nil {
-		log.WithError(err).Fatal("Could not hash tree root genesis state")
-	}
-	go slots.CountdownToGenesis(ctx, genesisTime, uint64(initializedState.NumValidators()), gRoot)
-
-	vr := bytesutil.ToBytes32(initializedState.GenesisValidatorsRoot())
-	if err := s.clockSetter.SetClock(startup.NewClock(genesisTime, vr)); err != nil {
-		log.WithError(err).Fatal("Failed to initialize blockchain service from execution start event")
-	}
-}
-
 // initializes the state and genesis block of the beacon chain to persistent storage
 // based on a genesis timestamp value obtained from the ChainStart event emitted
 // by the ETH1.0 Deposit Contract and the POWChain service of the node.
@@ -516,6 +467,57 @@ func (s *Service) removeStartupState() {
 	s.cfg.FinalizedStateAtStartUp = nil
 }
 
+// UpdateCustodyInfoInDB updates the custody information in the database.
+// It returns the (potentially updated) custody group count and the earliest available slot.
+func (s *Service) updateCustodyInfoInDB(slot primitives.Slot) (primitives.Slot, uint64, error) {
+	isSubscribedToAllDataSubnets := flags.Get().SubscribeAllDataSubnets
+
+	beaconConfig := params.BeaconConfig()
+	custodyRequirement := beaconConfig.CustodyRequirement
+
+	// Check if the node was previously subscribed to all data subnets, and if so,
+	// store the new status accordingly.
+	wasSubscribedToAllDataSubnets, err := s.cfg.BeaconDB.UpdateSubscribedToAllDataSubnets(s.ctx, isSubscribedToAllDataSubnets)
+	if err != nil {
+		log.WithError(err).Error("Could not update subscription status to all data subnets")
+	}
+
+	// Warn the user if the node was previously subscribed to all data subnets and is not any more.
+	if wasSubscribedToAllDataSubnets && !isSubscribedToAllDataSubnets {
+		log.Warnf(
+			"Because the flag `--%s` was previously used, the node will still subscribe to all data subnets.",
+			flags.SubscribeAllDataSubnets.Name,
+		)
+	}
+
+	// Compute the custody group count.
+	custodyGroupCount := custodyRequirement
+	if isSubscribedToAllDataSubnets {
+		custodyGroupCount = beaconConfig.NumberOfColumns
+	}
+
+	// Safely compute the fulu fork slot.
+	fuluForkSlot, err := fuluForkSlot()
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "fulu fork slot")
+	}
+
+	// If slot is before the fulu fork slot, then use the earliest stored slot as the reference slot.
+	if slot < fuluForkSlot {
+		slot, err = s.cfg.BeaconDB.EarliestSlot(s.ctx)
+		if err != nil {
+			return 0, 0, errors.Wrap(err, "earliest slot")
+		}
+	}
+
+	earliestAvailableSlot, custodyGroupCount, err := s.cfg.BeaconDB.UpdateCustodyInfo(s.ctx, slot, custodyGroupCount)
+	if err != nil {
+		return 0, 0, errors.Wrap(err, "update custody info")
+	}
+
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
 func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db db.HeadAccessDatabase) {
 	currentTime := prysmTime.Now()
 	if currentTime.After(genesisTime) {
@@ -532,3 +534,19 @@ func spawnCountdownIfPreGenesis(ctx context.Context, genesisTime time.Time, db d
 	}
 	go slots.CountdownToGenesis(ctx, genesisTime, uint64(gState.NumValidators()), gRoot)
 }
+
+func fuluForkSlot() (primitives.Slot, error) {
+	beaconConfig := params.BeaconConfig()
+
+	fuluForkEpoch := beaconConfig.FuluForkEpoch
+	if fuluForkEpoch == beaconConfig.FarFutureEpoch {
+		return beaconConfig.FarFutureSlot, nil
+	}
+
+	forkFuluSlot, err := slots.EpochStart(fuluForkEpoch)
+	if err != nil {
+		return 0, errors.Wrap(err, "epoch start")
+	}
+
+	return forkFuluSlot, nil
+}

beacon-chain/blockchain/service_test.go

@@ -31,6 +31,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/trie"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -51,6 +52,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		srv.Stop()
 	})
 	bState, _ := util.DeterministicGenesisState(t, 10)
+	genesis.StoreStateDuringTest(t, bState)
 	pbState, err := state_native.ProtobufBeaconStatePhase0(bState.ToProtoUnsafe())
 	require.NoError(t, err)
 	mockTrie, err := trie.NewTrie(0)
@@ -71,20 +73,22 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		DepositContainers: []*ethpb.DepositContainer{},
 	})
 	require.NoError(t, err)
+
+	depositCache, err := depositsnapshot.New()
+	require.NoError(t, err)
+
 	web3Service, err = execution.NewService(
 		ctx,
 		execution.WithDatabase(beaconDB),
 		execution.WithHttpEndpoint(endpoint),
 		execution.WithDepositContractAddress(common.Address{}),
+		execution.WithDepositCache(depositCache),
 	)
 	require.NoError(t, err, "Unable to set up web3 service")
 
 	attService, err := attestations.NewService(ctx, &attestations.Config{Pool: attestations.NewPool()})
 	require.NoError(t, err)
 
-	depositCache, err := depositsnapshot.New()
-	require.NoError(t, err)
-
 	fc := doublylinkedtree.New()
 	stateGen := stategen.New(beaconDB, fc)
 	// Safe a state in stategen to purposes of testing a service stop / shutdown.
@@ -396,24 +400,6 @@ func TestServiceStop_SaveCachedBlocks(t *testing.T) {
 	require.Equal(t, true, s.cfg.BeaconDB.HasBlock(s.ctx, r))
 }
 
-func TestProcessChainStartTime_ReceivedFeed(t *testing.T) {
-	ctx := t.Context()
-	beaconDB := testDB.SetupDB(t)
-	service := setupBeaconChain(t, beaconDB)
-	mgs := &MockClockSetter{}
-	service.clockSetter = mgs
-	gt := time.Now()
-	service.onExecutionChainStart(t.Context(), gt)
-	gs, err := beaconDB.GenesisState(ctx)
-	require.NoError(t, err)
-	require.NotEqual(t, nil, gs)
-	require.Equal(t, 32, len(gs.GenesisValidatorsRoot()))
-	var zero [32]byte
-	require.DeepNotEqual(t, gs.GenesisValidatorsRoot(), zero[:])
-	require.Equal(t, gt, mgs.G.GenesisTime())
-	require.Equal(t, bytesutil.ToBytes32(gs.GenesisValidatorsRoot()), mgs.G.GenesisValidatorsRoot())
-}
-
 func BenchmarkHasBlockDB(b *testing.B) {
 	ctx := b.Context()
 	s := testServiceWithDB(b)

beacon-chain/blockchain/setup_forkchoice.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"slices"
 
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
@@ -20,7 +21,7 @@ func (s *Service) setupForkchoice(st state.BeaconState) error {
 		return errors.Wrap(err, "could not set up forkchoice checkpoints")
 	}
 	if err := s.setupForkchoiceTree(st); err != nil {
-		return errors.Wrap(err, "could not set up forkchoice root")
+		return errors.Wrap(err, "could not set up forkchoice tree")
 	}
 	if err := s.initializeHead(s.ctx, st); err != nil {
 		return errors.Wrap(err, "could not initialize head from db")
@@ -30,24 +31,24 @@ func (s *Service) setupForkchoice(st state.BeaconState) error {
 
 func (s *Service) startupHeadRoot() [32]byte {
 	headStr := features.Get().ForceHead
-	cp := s.FinalizedCheckpt()
-	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	jp := s.CurrentJustifiedCheckpt()
+	jRoot := s.ensureRootNotZeros([32]byte(jp.Root))
 	if headStr == "" {
-		return fRoot
+		return jRoot
 	}
 	if headStr == "head" {
 		root, err := s.cfg.BeaconDB.HeadBlockRoot()
 		if err != nil {
-			log.WithError(err).Error("Could not get head block root, starting with finalized block as head")
-			return fRoot
+			log.WithError(err).Error("Could not get head block root, starting with justified block as head")
+			return jRoot
 		}
 		log.Infof("Using Head root of %#x", root)
 		return root
 	}
 	root, err := bytesutil.DecodeHexWithLength(headStr, 32)
 	if err != nil {
-		log.WithError(err).Error("Could not parse head root, starting with finalized block as head")
-		return fRoot
+		log.WithError(err).Error("Could not parse head root, starting with justified block as head")
+		return jRoot
 	}
 	return [32]byte(root)
 }
@@ -112,6 +113,7 @@ func (s *Service) buildForkchoiceChain(ctx context.Context, head interfaces.Read
 			return nil, errors.New("head block is not a descendant of the finalized checkpoint")
 		}
 	}
+	slices.Reverse(chain)
 	return chain, nil
 }
 

beacon-chain/blockchain/setup_forkchoice_test.go

@@ -32,7 +32,7 @@ func Test_startupHeadRoot(t *testing.T) {
 		})
 		defer resetCfg()
 		require.Equal(t, service.startupHeadRoot(), gr)
-		require.LogsContain(t, hook, "Could not get head block root, starting with finalized block as head")
+		require.LogsContain(t, hook, "Could not get head block root, starting with justified block as head")
 	})
 
 	st, _ := util.DeterministicGenesisState(t, 64)
@@ -124,5 +124,5 @@ func Test_setupForkchoiceTree_Head(t *testing.T) {
 	require.NotEqual(t, fRoot, root)
 	require.Equal(t, root, service.startupHeadRoot())
 	require.NoError(t, service.setupForkchoiceTree(st))
-	require.Equal(t, 2, service.cfg.ForkChoiceStore.NodeCount())
+	require.Equal(t, 3, service.cfg.ForkChoiceStore.NodeCount())
 }

beacon-chain/blockchain/setup_test.go

@@ -11,25 +11,26 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
-	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	mockExecution "github.com/OffchainLabs/prysm/v6/beacon-chain/execution/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
+	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
-	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -54,6 +55,7 @@ type mockBroadcaster struct {
 
 type mockAccessor struct {
 	mockBroadcaster
+	mockCustodyManager
 	p2pTesting.MockPeerManager
 }
 
@@ -87,7 +89,7 @@ func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
-func (mb *mockBroadcaster) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar, _ ...chan<- bool) error {
+func (mb *mockBroadcaster) BroadcastDataColumnSidecar(_ uint64, _ blocks.VerifiedRODataColumn) error {
 	mb.broadcastCalled = true
 	return nil
 }
@@ -97,6 +99,43 @@ func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.Sig
 
 var _ p2p.Broadcaster = (*mockBroadcaster)(nil)
 
+// mockCustodyManager is a mock implementation of p2p.CustodyManager
+type mockCustodyManager struct {
+	mut                   sync.RWMutex
+	earliestAvailableSlot primitives.Slot
+	custodyGroupCount     uint64
+}
+
+func (dch *mockCustodyManager) EarliestAvailableSlot() (primitives.Slot, error) {
+	dch.mut.RLock()
+	defer dch.mut.RUnlock()
+
+	return dch.earliestAvailableSlot, nil
+}
+
+func (dch *mockCustodyManager) CustodyGroupCount() (uint64, error) {
+	dch.mut.RLock()
+	defer dch.mut.RUnlock()
+
+	return dch.custodyGroupCount, nil
+}
+
+func (dch *mockCustodyManager) UpdateCustodyInfo(earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	dch.mut.Lock()
+	defer dch.mut.Unlock()
+
+	dch.earliestAvailableSlot = earliestAvailableSlot
+	dch.custodyGroupCount = custodyGroupCount
+
+	return earliestAvailableSlot, custodyGroupCount, nil
+}
+
+func (dch *mockCustodyManager) CustodyGroupCountFromPeer(peer.ID) uint64 {
+	return 0
+}
+
+var _ p2p.CustodyManager = (*mockCustodyManager)(nil)
+
 type testServiceRequirements struct {
 	ctx     context.Context
 	db      db.Database

beacon-chain/blockchain/testing/mock.go

@@ -723,7 +723,8 @@ func (c *ChainService) ReceiveDataColumn(dc blocks.VerifiedRODataColumn) error {
 }
 
 // ReceiveDataColumns implements the same method in chain service
-func (*ChainService) ReceiveDataColumns(_ []blocks.VerifiedRODataColumn) error {
+func (c *ChainService) ReceiveDataColumns(dcs []blocks.VerifiedRODataColumn) error {
+	c.DataColumns = append(c.DataColumns, dcs...)
 	return nil
 }
 

beacon-chain/builder/service.go

@@ -24,7 +24,8 @@ var ErrNoBuilder = errors.New("builder endpoint not configured")
 
 // BlockBuilder defines the interface for interacting with the block builder
 type BlockBuilder interface {
-	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error)
+	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) error
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error)
 	RegisterValidator(ctx context.Context, reg []*ethpb.SignedValidatorRegistrationV1) error
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
@@ -68,7 +69,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 			log.WithError(err).Error("Failed to check builder status")
 		} else {
 			log.WithField("endpoint", s.c.NodeURL()).Info("Builder has been configured")
-			log.Warn("Outsourcing block construction to external builders adds non-trivial delay to block propagation time.  " +
+			log.Warn("Outsourcing block construction to external builders adds non-trivial delay to block propagation time. " +
 				"Builder-constructed blocks or fallback blocks may get orphaned. Use at your own risk!")
 		}
 	}
@@ -87,7 +88,7 @@ func (s *Service) Stop() error {
 }
 
 // SubmitBlindedBlock submits a blinded block to the builder relay network.
-func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlock")
 	defer span.End()
 	start := time.Now()
@@ -101,6 +102,22 @@ func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlyS
 	return s.c.SubmitBlindedBlock(ctx, b)
 }
 
+// SubmitBlindedBlockPostFulu submits a blinded block to the builder relay network post-Fulu.
+// After Fulu, relays only return status codes (no payload).
+func (s *Service) SubmitBlindedBlockPostFulu(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) error {
+	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlockPostFulu")
+	defer span.End()
+	start := time.Now()
+	defer func() {
+		submitBlindedBlockLatency.Observe(float64(time.Since(start).Milliseconds()))
+	}()
+	if s.c == nil {
+		return ErrNoBuilder
+	}
+
+	return s.c.SubmitBlindedBlockPostFulu(ctx, b)
+}
+
 // GetHeader retrieves the header for a given slot and parent hash from the builder relay network.
 func (s *Service) GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.GetHeader")

beacon-chain/builder/testing/mock.go

@@ -24,20 +24,22 @@ type Config struct {
 
 // MockBuilderService to mock builder.
 type MockBuilderService struct {
-	HasConfigured         bool
-	Payload               *v1.ExecutionPayload
-	PayloadCapella        *v1.ExecutionPayloadCapella
-	PayloadDeneb          *v1.ExecutionPayloadDeneb
-	BlobBundle            *v1.BlobsBundle
-	ErrSubmitBlindedBlock error
-	Bid                   *ethpb.SignedBuilderBid
-	BidCapella            *ethpb.SignedBuilderBidCapella
-	BidDeneb              *ethpb.SignedBuilderBidDeneb
-	BidElectra            *ethpb.SignedBuilderBidElectra
-	RegistrationCache     *cache.RegistrationCache
-	ErrGetHeader          error
-	ErrRegisterValidator  error
-	Cfg                   *Config
+	HasConfigured                 bool
+	Payload                       *v1.ExecutionPayload
+	PayloadCapella                *v1.ExecutionPayloadCapella
+	PayloadDeneb                  *v1.ExecutionPayloadDeneb
+	BlobBundle                    *v1.BlobsBundle
+	BlobBundleV2                  *v1.BlobsBundleV2
+	ErrSubmitBlindedBlock         error
+	ErrSubmitBlindedBlockPostFulu error
+	Bid                           *ethpb.SignedBuilderBid
+	BidCapella                    *ethpb.SignedBuilderBidCapella
+	BidDeneb                      *ethpb.SignedBuilderBidDeneb
+	BidElectra                    *ethpb.SignedBuilderBidElectra
+	RegistrationCache             *cache.RegistrationCache
+	ErrGetHeader                  error
+	ErrRegisterValidator          error
+	Cfg                           *Config
 }
 
 // Configured for mocking.
@@ -46,7 +48,7 @@ func (s *MockBuilderService) Configured() bool {
 }
 
 // SubmitBlindedBlock for mocking.
-func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, *v1.BlobsBundle, error) {
+func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error) {
 	switch b.Version() {
 	case version.Bellatrix:
 		w, err := blocks.WrappedExecutionPayload(s.Payload)
@@ -66,6 +68,16 @@ func (s *MockBuilderService) SubmitBlindedBlock(_ context.Context, b interfaces.
 			return nil, nil, errors.Wrap(err, "could not wrap deneb payload")
 		}
 		return w, s.BlobBundle, s.ErrSubmitBlindedBlock
+	case version.Fulu:
+		w, err := blocks.WrappedExecutionPayloadDeneb(s.PayloadDeneb)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "could not wrap deneb payload for fulu")
+		}
+		// For Fulu, return BlobsBundleV2 if available, otherwise regular BlobsBundle
+		if s.BlobBundleV2 != nil {
+			return w, s.BlobBundleV2, s.ErrSubmitBlindedBlock
+		}
+		return w, s.BlobBundle, s.ErrSubmitBlindedBlock
 	default:
 		return nil, nil, errors.New("unknown block version for mocking")
 	}
@@ -104,3 +116,8 @@ func (s *MockBuilderService) RegistrationByValidatorID(ctx context.Context, id p
 func (s *MockBuilderService) RegisterValidator(context.Context, []*ethpb.SignedValidatorRegistrationV1) error {
 	return s.ErrRegisterValidator
 }
+
+// SubmitBlindedBlockPostFulu for mocking.
+func (s *MockBuilderService) SubmitBlindedBlockPostFulu(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) error {
+	return s.ErrSubmitBlindedBlockPostFulu
+}

beacon-chain/cache/sync_committee.go

@@ -67,6 +67,30 @@ func (s *SyncCommitteeCache) Clear() {
 	s.cache = cache.NewFIFO(keyFn)
 }
 
+// CurrentPeriodPositions returns current period positions of validator indices with respect with
+// sync committee. If any input validator index has no assignment, an empty list will be returned
+// for that validator. If the input root does not exist in cache, `ErrNonExistingSyncCommitteeKey` is returned.
+// Manual checking of state for index position in state is recommended when `ErrNonExistingSyncCommitteeKey` is returned.
+func (s *SyncCommitteeCache) CurrentPeriodPositions(root [32]byte, indices []primitives.ValidatorIndex) ([][]primitives.CommitteeIndex, error) {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	pos, err := s.positionsInCommittee(root, indices)
+	if err != nil {
+		return nil, err
+	}
+	result := make([][]primitives.CommitteeIndex, len(pos))
+	for i, p := range pos {
+		if p == nil {
+			result[i] = []primitives.CommitteeIndex{}
+		} else {
+			result[i] = p.currentPeriod
+		}
+	}
+
+	return result, nil
+}
+
 // CurrentPeriodIndexPosition returns current period index position of a validator index with respect with
 // sync committee. If the input validator index has no assignment, an empty list will be returned.
 // If the input root does not exist in cache, `ErrNonExistingSyncCommitteeKey` is returned.
@@ -104,11 +128,7 @@ func (s *SyncCommitteeCache) NextPeriodIndexPosition(root [32]byte, valIdx primi
 	return pos.nextPeriod, nil
 }
 
-// Helper function for `CurrentPeriodIndexPosition` and `NextPeriodIndexPosition` to return a mapping
-// of validator index to its index(s) position in the sync committee.
-func (s *SyncCommitteeCache) idxPositionInCommittee(
-	root [32]byte, valIdx primitives.ValidatorIndex,
-) (*positionInCommittee, error) {
+func (s *SyncCommitteeCache) positionsInCommittee(root [32]byte, indices []primitives.ValidatorIndex) ([]*positionInCommittee, error) {
 	obj, exists, err := s.cache.GetByKey(key(root))
 	if err != nil {
 		return nil, err
@@ -121,13 +141,33 @@ func (s *SyncCommitteeCache) idxPositionInCommittee(
 	if !ok {
 		return nil, errNotSyncCommitteeIndexPosition
 	}
-	idxInCommittee, ok := item.vIndexToPositionMap[valIdx]
-	if !ok {
-		SyncCommitteeCacheMiss.Inc()
+	result := make([]*positionInCommittee, len(indices))
+	for i, idx := range indices {
+		idxInCommittee, ok := item.vIndexToPositionMap[idx]
+		if ok {
+			SyncCommitteeCacheHit.Inc()
+			result[i] = idxInCommittee
+		} else {
+			SyncCommitteeCacheMiss.Inc()
+			result[i] = nil
+		}
+	}
+	return result, nil
+}
+
+// Helper function for `CurrentPeriodIndexPosition` and `NextPeriodIndexPosition` to return a mapping
+// of validator index to its index(s) position in the sync committee.
+func (s *SyncCommitteeCache) idxPositionInCommittee(
+	root [32]byte, valIdx primitives.ValidatorIndex,
+) (*positionInCommittee, error) {
+	positions, err := s.positionsInCommittee(root, []primitives.ValidatorIndex{valIdx})
+	if err != nil {
+		return nil, err
+	}
+	if len(positions) == 0 {
 		return nil, nil
 	}
-	SyncCommitteeCacheHit.Inc()
-	return idxInCommittee, nil
+	return positions[0], nil
 }
 
 // UpdatePositionsInCommittee updates caching of validators position in sync committee in respect to

beacon-chain/cache/sync_committee_disabled.go

@@ -16,6 +16,11 @@ func NewSyncCommittee() *FakeSyncCommitteeCache {
 	return &FakeSyncCommitteeCache{}
 }
 
+// CurrentPeriodPositions -- fake
+func (s *FakeSyncCommitteeCache) CurrentPeriodPositions(root [32]byte, indices []primitives.ValidatorIndex) ([][]primitives.CommitteeIndex, error) {
+	return nil, nil
+}
+
 // CurrentEpochIndexPosition -- fake.
 func (s *FakeSyncCommitteeCache) CurrentPeriodIndexPosition(root [32]byte, valIdx primitives.ValidatorIndex) ([]primitives.CommitteeIndex, error) {
 	return nil, nil

beacon-chain/core/blocks/BUILD.bazel

@@ -41,7 +41,6 @@ go_library(
         "//encoding/ssz:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
-        "//network/forks:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",

beacon-chain/core/blocks/attester_slashing.go

@@ -5,6 +5,7 @@ import (
 	"sort"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
@@ -39,11 +40,11 @@ func ProcessAttesterSlashings(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashings []ethpb.AttSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	var err error
 	for _, slashing := range slashings {
-		beaconState, err = ProcessAttesterSlashing(ctx, beaconState, slashing, slashFunc)
+		beaconState, err = ProcessAttesterSlashing(ctx, beaconState, slashing, exitInfo)
 		if err != nil {
 			return nil, err
 		}
@@ -56,7 +57,7 @@ func ProcessAttesterSlashing(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashing ethpb.AttSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	if err := VerifyAttesterSlashing(ctx, beaconState, slashing); err != nil {
 		return nil, errors.Wrap(err, "could not verify attester slashing")
@@ -75,10 +76,9 @@ func ProcessAttesterSlashing(
 			return nil, err
 		}
 		if helpers.IsSlashableValidator(val.ActivationEpoch(), val.WithdrawableEpoch(), val.Slashed(), currentEpoch) {
-			beaconState, err = slashFunc(ctx, beaconState, primitives.ValidatorIndex(validatorIndex))
+			beaconState, err = validators.SlashValidator(ctx, beaconState, primitives.ValidatorIndex(validatorIndex), exitInfo)
 			if err != nil {
-				return nil, errors.Wrapf(err, "could not slash validator index %d",
-					validatorIndex)
+				return nil, errors.Wrapf(err, "could not slash validator index %d", validatorIndex)
 			}
 			slashedAny = true
 		}

beacon-chain/core/blocks/attester_slashing_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
@@ -44,11 +45,10 @@ func TestProcessAttesterSlashings_DataNotSlashable(t *testing.T) {
 				Target: &ethpb.Checkpoint{Epoch: 1}},
 		})}}
 
-	var registry []*ethpb.Validator
 	currentSlot := primitives.Slot(0)
 
 	beaconState, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
-		Validators: registry,
+		Validators: []*ethpb.Validator{{}},
 		Slot:       currentSlot,
 	})
 	require.NoError(t, err)
@@ -62,16 +62,15 @@ func TestProcessAttesterSlashings_DataNotSlashable(t *testing.T) {
 	for i, s := range b.Block.Body.AttesterSlashings {
 		ss[i] = s
 	}
-	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.SlashValidator)
+	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, "attestations are not slashable", err)
 }
 
 func TestProcessAttesterSlashings_IndexedAttestationFailedToVerify(t *testing.T) {
-	var registry []*ethpb.Validator
 	currentSlot := primitives.Slot(0)
 
 	beaconState, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
-		Validators: registry,
+		Validators: []*ethpb.Validator{{}},
 		Slot:       currentSlot,
 	})
 	require.NoError(t, err)
@@ -101,7 +100,7 @@ func TestProcessAttesterSlashings_IndexedAttestationFailedToVerify(t *testing.T)
 	for i, s := range b.Block.Body.AttesterSlashings {
 		ss[i] = s
 	}
-	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.SlashValidator)
+	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, "validator indices count exceeds MAX_VALIDATORS_PER_COMMITTEE", err)
 }
 
@@ -243,7 +242,7 @@ func TestProcessAttesterSlashings_AppliesCorrectStatus(t *testing.T) {
 			currentSlot := 2 * params.BeaconConfig().SlotsPerEpoch
 			require.NoError(t, tc.st.SetSlot(currentSlot))
 
-			newState, err := blocks.ProcessAttesterSlashings(t.Context(), tc.st, []ethpb.AttSlashing{tc.slashing}, v.SlashValidator)
+			newState, err := blocks.ProcessAttesterSlashings(t.Context(), tc.st, []ethpb.AttSlashing{tc.slashing}, v.ExitInformation(tc.st))
 			require.NoError(t, err)
 			newRegistry := newState.Validators()
 
@@ -265,3 +264,83 @@ func TestProcessAttesterSlashings_AppliesCorrectStatus(t *testing.T) {
 		})
 	}
 }
+
+func TestProcessAttesterSlashing_ExitEpochGetsUpdated(t *testing.T) {
+	st, keys := util.DeterministicGenesisStateElectra(t, 8)
+	bal, err := helpers.TotalActiveBalance(st)
+	require.NoError(t, err)
+	perEpochChurn := helpers.ActivationExitChurnLimit(primitives.Gwei(bal))
+	vals := st.Validators()
+
+	// We set the total effective balance of slashed validators
+	// higher than the churn limit for a single epoch.
+	vals[0].EffectiveBalance = uint64(perEpochChurn / 3)
+	vals[1].EffectiveBalance = uint64(perEpochChurn / 3)
+	vals[2].EffectiveBalance = uint64(perEpochChurn / 3)
+	vals[3].EffectiveBalance = uint64(perEpochChurn / 3)
+	require.NoError(t, st.SetValidators(vals))
+
+	sl1att1 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		Data: &ethpb.AttestationData{
+			Source: &ethpb.Checkpoint{Epoch: 1},
+		},
+		AttestingIndices: []uint64{0, 1},
+	})
+	sl1att2 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		AttestingIndices: []uint64{0, 1},
+	})
+	slashing1 := &ethpb.AttesterSlashingElectra{
+		Attestation_1: sl1att1,
+		Attestation_2: sl1att2,
+	}
+	sl2att1 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		Data: &ethpb.AttestationData{
+			Source: &ethpb.Checkpoint{Epoch: 1},
+		},
+		AttestingIndices: []uint64{2, 3},
+	})
+	sl2att2 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		AttestingIndices: []uint64{2, 3},
+	})
+	slashing2 := &ethpb.AttesterSlashingElectra{
+		Attestation_1: sl2att1,
+		Attestation_2: sl2att2,
+	}
+
+	domain, err := signing.Domain(st.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorsRoot())
+	require.NoError(t, err)
+
+	signingRoot, err := signing.ComputeSigningRoot(sl1att1.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 := keys[0].Sign(signingRoot[:])
+	sig1 := keys[1].Sign(signingRoot[:])
+	aggregateSig := bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl1att1.Signature = aggregateSig.Marshal()
+
+	signingRoot, err = signing.ComputeSigningRoot(sl1att2.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = keys[0].Sign(signingRoot[:])
+	sig1 = keys[1].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl1att2.Signature = aggregateSig.Marshal()
+
+	signingRoot, err = signing.ComputeSigningRoot(sl2att1.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = keys[2].Sign(signingRoot[:])
+	sig1 = keys[3].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl2att1.Signature = aggregateSig.Marshal()
+
+	signingRoot, err = signing.ComputeSigningRoot(sl2att2.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = keys[2].Sign(signingRoot[:])
+	sig1 = keys[3].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl2att2.Signature = aggregateSig.Marshal()
+
+	exitInfo := v.ExitInformation(st)
+	assert.Equal(t, primitives.Epoch(0), exitInfo.HighestExitEpoch)
+	_, err = blocks.ProcessAttesterSlashings(t.Context(), st, []ethpb.AttSlashing{slashing1, slashing2}, exitInfo)
+	require.NoError(t, err)
+	assert.Equal(t, primitives.Epoch(6), exitInfo.HighestExitEpoch)
+}

beacon-chain/core/blocks/block_operations_fuzz_test.go

@@ -191,7 +191,7 @@ func TestFuzzProcessProposerSlashings_10000(t *testing.T) {
 		fuzzer.Fuzz(p)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessProposerSlashings(ctx, s, []*ethpb.ProposerSlashing{p}, v.SlashValidator)
+		r, err := ProcessProposerSlashings(ctx, s, []*ethpb.ProposerSlashing{p}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and slashing: %v", r, err, state, p)
 		}
@@ -224,7 +224,7 @@ func TestFuzzProcessAttesterSlashings_10000(t *testing.T) {
 		fuzzer.Fuzz(a)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessAttesterSlashings(ctx, s, []ethpb.AttSlashing{a}, v.SlashValidator)
+		r, err := ProcessAttesterSlashings(ctx, s, []ethpb.AttSlashing{a}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and slashing: %v", r, err, state, a)
 		}
@@ -334,7 +334,7 @@ func TestFuzzProcessVoluntaryExits_10000(t *testing.T) {
 		fuzzer.Fuzz(e)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessVoluntaryExits(ctx, s, []*ethpb.SignedVoluntaryExit{e})
+		r, err := ProcessVoluntaryExits(ctx, s, []*ethpb.SignedVoluntaryExit{e}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and exit: %v", r, err, state, e)
 		}
@@ -351,7 +351,7 @@ func TestFuzzProcessVoluntaryExitsNoVerify_10000(t *testing.T) {
 		fuzzer.Fuzz(e)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessVoluntaryExits(t.Context(), s, []*ethpb.SignedVoluntaryExit{e})
+		r, err := ProcessVoluntaryExits(t.Context(), s, []*ethpb.SignedVoluntaryExit{e}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and block: %v", r, err, state, e)
 		}

beacon-chain/core/blocks/block_regression_test.go

@@ -94,7 +94,7 @@ func TestProcessAttesterSlashings_RegressionSlashableIndices(t *testing.T) {
 	for i, s := range b.Block.Body.AttesterSlashings {
 		ss[i] = s
 	}
-	newState, err := blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.SlashValidator)
+	newState, err := blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 	newRegistry := newState.Validators()
 	if !newRegistry[expectedSlashedVal].Slashed {

beacon-chain/core/blocks/exit.go

@@ -9,7 +9,6 @@ import (
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -50,13 +49,12 @@ func ProcessVoluntaryExits(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	exits []*ethpb.SignedVoluntaryExit,
+	exitInfo *v.ExitInfo,
 ) (state.BeaconState, error) {
 	// Avoid calculating the epoch churn if no exits exist.
 	if len(exits) == 0 {
 		return beaconState, nil
 	}
-	maxExitEpoch, churn := v.MaxExitEpochAndChurn(beaconState)
-	var exitEpoch primitives.Epoch
 	for idx, exit := range exits {
 		if exit == nil || exit.Exit == nil {
 			return nil, errors.New("nil voluntary exit in block body")
@@ -68,15 +66,8 @@ func ProcessVoluntaryExits(
 		if err := VerifyExitAndSignature(val, beaconState, exit); err != nil {
 			return nil, errors.Wrapf(err, "could not verify exit %d", idx)
 		}
-		beaconState, exitEpoch, err = v.InitiateValidatorExit(ctx, beaconState, exit.Exit.ValidatorIndex, maxExitEpoch, churn)
-		if err == nil {
-			if exitEpoch > maxExitEpoch {
-				maxExitEpoch = exitEpoch
-				churn = 1
-			} else if exitEpoch == maxExitEpoch {
-				churn++
-			}
-		} else if !errors.Is(err, v.ErrValidatorAlreadyExited) {
+		beaconState, err = v.InitiateValidatorExit(ctx, beaconState, exit.Exit.ValidatorIndex, exitInfo)
+		if err != nil && !errors.Is(err, v.ErrValidatorAlreadyExited) {
 			return nil, err
 		}
 	}

beacon-chain/core/blocks/exit_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -46,7 +47,7 @@ func TestProcessVoluntaryExits_NotActiveLongEnoughToExit(t *testing.T) {
 	}
 
 	want := "validator has not been active long enough to exit"
-	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits)
+	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits, validators.ExitInformation(state))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -76,7 +77,7 @@ func TestProcessVoluntaryExits_ExitAlreadySubmitted(t *testing.T) {
 	}
 
 	want := "validator with index 0 has already submitted an exit, which will take place at epoch: 10"
-	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits)
+	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits, validators.ExitInformation(state))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -124,7 +125,7 @@ func TestProcessVoluntaryExits_AppliesCorrectStatus(t *testing.T) {
 		},
 	}
 
-	newState, err := blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits)
+	newState, err := blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits, validators.ExitInformation(state))
 	require.NoError(t, err, "Could not process exits")
 	newRegistry := newState.Validators()
 	if newRegistry[0].ExitEpoch != helpers.ActivationExitEpoch(primitives.Epoch(state.Slot()/params.BeaconConfig().SlotsPerEpoch)) {

beacon-chain/core/blocks/genesis.go

@@ -184,45 +184,54 @@ func NewGenesisBlockForState(ctx context.Context, st state.BeaconState) (interfa
 		})
 	case *ethpb.BeaconStateElectra:
 		return blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockElectra{
-			Block: &ethpb.BeaconBlockElectra{
-				ParentRoot: params.BeaconConfig().ZeroHash[:],
-				StateRoot:  root[:],
-				Body: &ethpb.BeaconBlockBodyElectra{
-					RandaoReveal: make([]byte, 96),
-					Eth1Data: &ethpb.Eth1Data{
-						DepositRoot: make([]byte, 32),
-						BlockHash:   make([]byte, 32),
-					},
-					Graffiti: make([]byte, 32),
-					SyncAggregate: &ethpb.SyncAggregate{
-						SyncCommitteeBits:      make([]byte, fieldparams.SyncCommitteeLength/8),
-						SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
-					},
-					ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
-						ParentHash:    make([]byte, 32),
-						FeeRecipient:  make([]byte, 20),
-						StateRoot:     make([]byte, 32),
-						ReceiptsRoot:  make([]byte, 32),
-						LogsBloom:     make([]byte, 256),
-						PrevRandao:    make([]byte, 32),
-						ExtraData:     make([]byte, 0),
-						BaseFeePerGas: make([]byte, 32),
-						BlockHash:     make([]byte, 32),
-						Transactions:  make([][]byte, 0),
-						Withdrawals:   make([]*enginev1.Withdrawal, 0),
-					},
-					BlsToExecutionChanges: make([]*ethpb.SignedBLSToExecutionChange, 0),
-					BlobKzgCommitments:    make([][]byte, 0),
-					ExecutionRequests: &enginev1.ExecutionRequests{
-						Withdrawals:    make([]*enginev1.WithdrawalRequest, 0),
-						Deposits:       make([]*enginev1.DepositRequest, 0),
-						Consolidations: make([]*enginev1.ConsolidationRequest, 0),
-					},
-				},
-			},
+			Block:     electraGenesisBlock(root),
+			Signature: params.BeaconConfig().EmptySignature[:],
+		})
+	case *ethpb.BeaconStateFulu:
+		return blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockFulu{
+			Block:     electraGenesisBlock(root),
 			Signature: params.BeaconConfig().EmptySignature[:],
 		})
 	default:
 		return nil, ErrUnrecognizedState
 	}
 }
+
+func electraGenesisBlock(root [fieldparams.RootLength]byte) *ethpb.BeaconBlockElectra {
+	return &ethpb.BeaconBlockElectra{
+		ParentRoot: params.BeaconConfig().ZeroHash[:],
+		StateRoot:  root[:],
+		Body: &ethpb.BeaconBlockBodyElectra{
+			RandaoReveal: make([]byte, 96),
+			Eth1Data: &ethpb.Eth1Data{
+				DepositRoot: make([]byte, 32),
+				BlockHash:   make([]byte, 32),
+			},
+			Graffiti: make([]byte, 32),
+			SyncAggregate: &ethpb.SyncAggregate{
+				SyncCommitteeBits:      make([]byte, fieldparams.SyncCommitteeLength/8),
+				SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+			},
+			ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
+				ParentHash:    make([]byte, 32),
+				FeeRecipient:  make([]byte, 20),
+				StateRoot:     make([]byte, 32),
+				ReceiptsRoot:  make([]byte, 32),
+				LogsBloom:     make([]byte, 256),
+				PrevRandao:    make([]byte, 32),
+				ExtraData:     make([]byte, 0),
+				BaseFeePerGas: make([]byte, 32),
+				BlockHash:     make([]byte, 32),
+				Transactions:  make([][]byte, 0),
+				Withdrawals:   make([]*enginev1.Withdrawal, 0),
+			},
+			BlsToExecutionChanges: make([]*ethpb.SignedBLSToExecutionChange, 0),
+			BlobKzgCommitments:    make([][]byte, 0),
+			ExecutionRequests: &enginev1.ExecutionRequests{
+				Withdrawals:    make([]*enginev1.WithdrawalRequest, 0),
+				Deposits:       make([]*enginev1.DepositRequest, 0),
+				Consolidations: make([]*enginev1.ConsolidationRequest, 0),
+			},
+		},
+	}
+}

beacon-chain/core/blocks/proposer_slashing.go

@@ -7,9 +7,9 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
@@ -19,11 +19,6 @@ import (
 // ErrCouldNotVerifyBlockHeader is returned when a block header's signature cannot be verified.
 var ErrCouldNotVerifyBlockHeader = errors.New("could not verify beacon block header")
 
-type slashValidatorFunc func(
-	ctx context.Context,
-	st state.BeaconState,
-	vid primitives.ValidatorIndex) (state.BeaconState, error)
-
 // ProcessProposerSlashings is one of the operations performed
 // on each processed beacon block to slash proposers based on
 // slashing conditions if any slashable events occurred.
@@ -54,11 +49,11 @@ func ProcessProposerSlashings(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashings []*ethpb.ProposerSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	var err error
 	for _, slashing := range slashings {
-		beaconState, err = ProcessProposerSlashing(ctx, beaconState, slashing, slashFunc)
+		beaconState, err = ProcessProposerSlashing(ctx, beaconState, slashing, exitInfo)
 		if err != nil {
 			return nil, err
 		}
@@ -71,7 +66,7 @@ func ProcessProposerSlashing(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashing *ethpb.ProposerSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	var err error
 	if slashing == nil {
@@ -80,7 +75,7 @@ func ProcessProposerSlashing(
 	if err = VerifyProposerSlashing(beaconState, slashing); err != nil {
 		return nil, errors.Wrap(err, "could not verify proposer slashing")
 	}
-	beaconState, err = slashFunc(ctx, beaconState, slashing.Header_1.Header.ProposerIndex)
+	beaconState, err = validators.SlashValidator(ctx, beaconState, slashing.Header_1.Header.ProposerIndex, exitInfo)
 	if err != nil {
 		return nil, errors.Wrapf(err, "could not slash proposer index %d", slashing.Header_1.Header.ProposerIndex)
 	}

beacon-chain/core/blocks/proposer_slashing_test.go

@@ -50,7 +50,7 @@ func TestProcessProposerSlashings_UnmatchedHeaderSlots(t *testing.T) {
 		},
 	}
 	want := "mismatched header slots"
-	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.SlashValidator)
+	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -83,7 +83,7 @@ func TestProcessProposerSlashings_SameHeaders(t *testing.T) {
 		},
 	}
 	want := "expected slashing headers to differ"
-	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.SlashValidator)
+	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -133,7 +133,7 @@ func TestProcessProposerSlashings_ValidatorNotSlashable(t *testing.T) {
 		"validator with key %#x is not slashable",
 		bytesutil.ToBytes48(beaconState.Validators()[0].PublicKey),
 	)
-	_, err = blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.SlashValidator)
+	_, err = blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -172,7 +172,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatus(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()
@@ -220,7 +220,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusAltair(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()
@@ -268,7 +268,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusBellatrix(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()
@@ -316,7 +316,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusCapella(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()

beacon-chain/core/blocks/signature.go

@@ -11,7 +11,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/crypto/bls"
-	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/attestation"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -101,7 +100,7 @@ func VerifyBlockHeaderSignature(beaconState state.BeaconState, header *ethpb.Sig
 // via the respective epoch.
 func VerifyBlockSignatureUsingCurrentFork(beaconState state.ReadOnlyBeaconState, blk interfaces.ReadOnlySignedBeaconBlock, blkRoot [32]byte) error {
 	currentEpoch := slots.ToEpoch(blk.Block().Slot())
-	fork, err := forks.Fork(currentEpoch)
+	fork, err := params.Fork(currentEpoch)
 	if err != nil {
 		return err
 	}

beacon-chain/core/electra/registry_updates.go

@@ -84,8 +84,8 @@ func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) error {
 	// Handle validator ejections.
 	for _, idx := range eligibleForEjection {
 		var err error
-		// exitQueueEpoch and churn arguments are not used in electra.
-		st, _, err = validators.InitiateValidatorExit(ctx, st, idx, 0 /*exitQueueEpoch*/, 0 /*churn*/)
+		// exit info is not used in electra
+		st, err = validators.InitiateValidatorExit(ctx, st, idx, &validators.ExitInfo{})
 		if err != nil && !errors.Is(err, validators.ErrValidatorAlreadyExited) {
 			return fmt.Errorf("failed to initiate validator exit at index %d: %w", idx, err)
 		}

beacon-chain/core/electra/transition_no_verify_sig.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -46,18 +47,21 @@ var (
 //      # [New in Electra:EIP7251]
 //      for_ops(body.execution_payload.consolidation_requests, process_consolidation_request)
 
-func ProcessOperations(
-	ctx context.Context,
-	st state.BeaconState,
-	block interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
+func ProcessOperations(ctx context.Context, st state.BeaconState, block interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
+	var err error
+
 	// 6110 validations are in VerifyOperationLengths
 	bb := block.Body()
 	// Electra extends the altair operations.
-	st, err := ProcessProposerSlashings(ctx, st, bb.ProposerSlashings(), v.SlashValidator)
+	exitInfo := v.ExitInformation(st)
+	if err := helpers.UpdateTotalActiveBalanceCache(st, exitInfo.TotalActiveBalance); err != nil {
+		return nil, errors.Wrap(err, "could not update total active balance cache")
+	}
+	st, err = ProcessProposerSlashings(ctx, st, bb.ProposerSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process altair proposer slashing")
 	}
-	st, err = ProcessAttesterSlashings(ctx, st, bb.AttesterSlashings(), v.SlashValidator)
+	st, err = ProcessAttesterSlashings(ctx, st, bb.AttesterSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process altair attester slashing")
 	}
@@ -68,7 +72,7 @@ func ProcessOperations(
 	if _, err := ProcessDeposits(ctx, st, bb.Deposits()); err != nil { // new in electra
 		return nil, errors.Wrap(err, "could not process altair deposit")
 	}
-	st, err = ProcessVoluntaryExits(ctx, st, bb.VoluntaryExits())
+	st, err = ProcessVoluntaryExits(ctx, st, bb.VoluntaryExits(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process voluntary exits")
 	}

beacon-chain/core/electra/withdrawals.go

@@ -102,13 +102,13 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 			return nil, err
 		} else if n == params.BeaconConfig().PendingPartialWithdrawalsLimit && !isFullExitRequest {
 			// if the PendingPartialWithdrawalsLimit is met, the user would have paid for a partial withdrawal that's not included
-			log.Debugln("Skipping execution layer withdrawal request, PendingPartialWithdrawalsLimit reached")
+			log.Debug("Skipping execution layer withdrawal request, PendingPartialWithdrawalsLimit reached")
 			continue
 		}
 
 		vIdx, exists := st.ValidatorIndexByPubkey(bytesutil.ToBytes48(wr.ValidatorPubkey))
 		if !exists {
-			log.Debugf("Skipping execution layer withdrawal request, validator index for %s not found\n", hexutil.Encode(wr.ValidatorPubkey))
+			log.WithField("validator", hexutil.Encode(wr.ValidatorPubkey)).Debug("Skipping execution layer withdrawal request, validator index not found")
 			continue
 		}
 		validator, err := st.ValidatorAtIndexReadOnly(vIdx)
@@ -120,23 +120,23 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 		wc := validator.GetWithdrawalCredentials()
 		isCorrectSourceAddress := bytes.Equal(wc[12:], wr.SourceAddress)
 		if !hasCorrectCredential || !isCorrectSourceAddress {
-			log.Debugln("Skipping execution layer withdrawal request, wrong withdrawal credentials")
+			log.Debug("Skipping execution layer withdrawal request, wrong withdrawal credentials")
 			continue
 		}
 
 		// Verify the validator is active.
 		if !helpers.IsActiveValidatorUsingTrie(validator, currentEpoch) {
-			log.Debugln("Skipping execution layer withdrawal request, validator not active")
+			log.Debug("Skipping execution layer withdrawal request, validator not active")
 			continue
 		}
 		// Verify the validator has not yet submitted an exit.
 		if validator.ExitEpoch() != params.BeaconConfig().FarFutureEpoch {
-			log.Debugln("Skipping execution layer withdrawal request, validator has submitted an exit already")
+			log.Debug("Skipping execution layer withdrawal request, validator has submitted an exit already")
 			continue
 		}
 		// Verify the validator has been active long enough.
 		if currentEpoch < validator.ActivationEpoch().AddEpoch(params.BeaconConfig().ShardCommitteePeriod) {
-			log.Debugln("Skipping execution layer withdrawal request, validator has not been active long enough")
+			log.Debug("Skipping execution layer withdrawal request, validator has not been active long enough")
 			continue
 		}
 
@@ -147,9 +147,8 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 		if isFullExitRequest {
 			// Only exit validator if it has no pending withdrawals in the queue
 			if pendingBalanceToWithdraw == 0 {
-				maxExitEpoch, churn := validators.MaxExitEpochAndChurn(st)
 				var err error
-				st, _, err = validators.InitiateValidatorExit(ctx, st, vIdx, maxExitEpoch, churn)
+				st, err = validators.InitiateValidatorExit(ctx, st, vIdx, validators.ExitInformation(st))
 				if err != nil {
 					return nil, err
 				}

beacon-chain/core/epoch/epoch_processing.go

@@ -99,8 +99,7 @@ func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) (state.Be
 	for _, idx := range eligibleForEjection {
 		// Here is fine to do a quadratic loop since this should
 		// barely happen
-		maxExitEpoch, churn := validators.MaxExitEpochAndChurn(st)
-		st, _, err = validators.InitiateValidatorExit(ctx, st, idx, maxExitEpoch, churn)
+		st, err = validators.InitiateValidatorExit(ctx, st, idx, validators.ExitInformation(st))
 		if err != nil && !errors.Is(err, validators.ErrValidatorAlreadyExited) {
 			return nil, errors.Wrapf(err, "could not initiate exit for validator %d", idx)
 		}

beacon-chain/core/fulu/transition.go

@@ -16,10 +16,10 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	if err := electra.ProcessEpoch(ctx, state); err != nil {
 		return errors.Wrap(err, "could not process epoch in fulu transition")
 	}
-	return processProposerLookahead(ctx, state)
+	return ProcessProposerLookahead(ctx, state)
 }
 
-func processProposerLookahead(ctx context.Context, state state.BeaconState) error {
+func ProcessProposerLookahead(ctx context.Context, state state.BeaconState) error {
 	_, span := trace.StartSpan(ctx, "fulu.processProposerLookahead")
 	defer span.End()
 

beacon-chain/core/fulu/upgrade.go

@@ -15,7 +15,7 @@ import (
 )
 
 // UpgradeToFulu updates inputs a generic state to return the version Fulu state.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/fork.md#upgrading-the-state
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/fork.md#upgrading-the-state
 func UpgradeToFulu(ctx context.Context, beaconState state.BeaconState) (state.BeaconState, error) {
 	currentSyncCommittee, err := beaconState.CurrentSyncCommittee()
 	if err != nil {

beacon-chain/core/helpers/BUILD.bazel

@@ -10,6 +10,7 @@ go_library(
         "legacy.go",
         "metrics.go",
         "randao.go",
+        "ranges.go",
         "rewards_penalties.go",
         "shuffle.go",
         "sync_committee.go",
@@ -56,6 +57,7 @@ go_test(
         "private_access_fuzz_noop_test.go",  # keep
         "private_access_test.go",
         "randao_test.go",
+        "ranges_test.go",
         "rewards_penalties_test.go",
         "shuffle_test.go",
         "sync_committee_test.go",

beacon-chain/core/helpers/beacon_committee.go

@@ -317,23 +317,15 @@ func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch pri
 	}
 
 	proposerAssignments := make(map[primitives.ValidatorIndex][]primitives.Slot)
-
-	originalStateSlot := state.Slot()
-
 	for slot := startSlot; slot < startSlot+params.BeaconConfig().SlotsPerEpoch; slot++ {
 		// Skip proposer assignment for genesis slot.
 		if slot == 0 {
 			continue
 		}
-		// Set the state's current slot.
-		if err := state.SetSlot(slot); err != nil {
-			return nil, err
-		}
-
 		// Determine the proposer index for the current slot.
-		i, err := BeaconProposerIndex(ctx, state)
+		i, err := BeaconProposerIndexAtSlot(ctx, state, slot)
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not check proposer at slot %d", state.Slot())
+			return nil, errors.Wrapf(err, "could not check proposer at slot %d", slot)
 		}
 
 		// Append the slot to the proposer's assignments.
@@ -342,12 +334,6 @@ func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch pri
 		}
 		proposerAssignments[i] = append(proposerAssignments[i], slot)
 	}
-
-	// Reset state back to its original slot.
-	if err := state.SetSlot(originalStateSlot); err != nil {
-		return nil, err
-	}
-
 	return proposerAssignments, nil
 }
 

beacon-chain/core/helpers/ranges.go

@@ -0,0 +1,62 @@
+package helpers
+
+import (
+	"fmt"
+	"slices"
+)
+
+// SortedSliceFromMap takes a map with uint64 keys and returns a sorted slice of the keys.
+func SortedSliceFromMap(toSort map[uint64]bool) []uint64 {
+	slice := make([]uint64, 0, len(toSort))
+	for key := range toSort {
+		slice = append(slice, key)
+	}
+
+	slices.Sort(slice)
+	return slice
+}
+
+// PrettySlice returns a pretty string representation of a sorted slice of uint64.
+// `sortedSlice` must be sorted in ascending order.
+// Example: [1,2,3,5,6,7,8,10] -> "1-3,5-8,10"
+func PrettySlice(sortedSlice []uint64) string {
+	if len(sortedSlice) == 0 {
+		return ""
+	}
+
+	var result string
+	start := sortedSlice[0]
+	end := sortedSlice[0]
+
+	for i := 1; i < len(sortedSlice); i++ {
+		if sortedSlice[i] == end+1 {
+			end = sortedSlice[i]
+			continue
+		}
+
+		if start == end {
+			result += fmt.Sprintf("%d,", start)
+			start = sortedSlice[i]
+			end = sortedSlice[i]
+			continue
+		}
+
+		result += fmt.Sprintf("%d-%d,", start, end)
+		start = sortedSlice[i]
+		end = sortedSlice[i]
+	}
+
+	if start == end {
+		result += fmt.Sprintf("%d", start)
+		return result
+	}
+
+	result += fmt.Sprintf("%d-%d", start, end)
+	return result
+}
+
+// SortedPrettySliceFromMap combines SortedSliceFromMap and PrettySlice to return a pretty string representation of the keys in a map.
+func SortedPrettySliceFromMap(toSort map[uint64]bool) string {
+	sorted := SortedSliceFromMap(toSort)
+	return PrettySlice(sorted)
+}

beacon-chain/core/helpers/ranges_test.go

@@ -0,0 +1,64 @@
+package helpers_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestSortedSliceFromMap(t *testing.T) {
+	input := map[uint64]bool{5: true, 3: true, 8: true, 1: true}
+	expected := []uint64{1, 3, 5, 8}
+
+	actual := helpers.SortedSliceFromMap(input)
+	require.Equal(t, len(expected), len(actual))
+
+	for i := range expected {
+		require.Equal(t, expected[i], actual[i])
+	}
+}
+
+func TestPrettySlice(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    []uint64
+		expected string
+	}{
+		{
+			name:     "empty slice",
+			input:    []uint64{},
+			expected: "",
+		},
+		{
+			name:     "only distinct elements",
+			input:    []uint64{1, 3, 5, 7, 9},
+			expected: "1,3,5,7,9",
+		},
+		{
+			name:     "single range",
+			input:    []uint64{1, 2, 3, 4, 5},
+			expected: "1-5",
+		},
+		{
+			name:     "multiple ranges and distinct elements",
+			input:    []uint64{1, 2, 3, 5, 6, 7, 8, 10, 12, 13, 14},
+			expected: "1-3,5-8,10,12-14",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := helpers.PrettySlice(tt.input)
+			require.Equal(t, tt.expected, actual)
+		})
+	}
+}
+
+func TestSortedPrettySliceFromMap(t *testing.T) {
+	input := map[uint64]bool{5: true, 7: true, 8: true, 10: true}
+	expected := "5,7-8,10"
+
+	actual := helpers.SortedPrettySliceFromMap(input)
+	require.Equal(t, expected, actual)
+}

beacon-chain/core/helpers/rewards_penalties.go

@@ -87,6 +87,11 @@ func TotalActiveBalance(s state.ReadOnlyBeaconState) (uint64, error) {
 	return total, nil
 }
 
+// UpdateTotalActiveBalanceCache updates the cache with the given total active balance.
+func UpdateTotalActiveBalanceCache(s state.BeaconState, total uint64) error {
+	return balanceCache.AddTotalEffectiveBalance(s, total)
+}
+
 // IncreaseBalance increases validator with the given 'index' balance by 'delta' in Gwei.
 //
 // Spec pseudocode definition:

beacon-chain/core/helpers/rewards_penalties_test.go

@@ -297,3 +297,30 @@ func TestIncreaseBadBalance_NotOK(t *testing.T) {
 		require.ErrorContains(t, "addition overflows", helpers.IncreaseBalance(state, test.i, test.nb))
 	}
 }
+
+func TestUpdateTotalActiveBalanceCache(t *testing.T) {
+	helpers.ClearCache()
+
+	// Create a test state with some validators
+	validators := []*ethpb.Validator{
+		{EffectiveBalance: 32 * 1e9, ExitEpoch: params.BeaconConfig().FarFutureEpoch, ActivationEpoch: 0},
+		{EffectiveBalance: 32 * 1e9, ExitEpoch: params.BeaconConfig().FarFutureEpoch, ActivationEpoch: 0},
+		{EffectiveBalance: 31 * 1e9, ExitEpoch: params.BeaconConfig().FarFutureEpoch, ActivationEpoch: 0},
+	}
+	state, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
+		Validators: validators,
+		Slot:       0,
+	})
+	require.NoError(t, err)
+
+	// Test updating cache with a specific total
+	testTotal := uint64(95 * 1e9) // 32 + 32 + 31 = 95
+	err = helpers.UpdateTotalActiveBalanceCache(state, testTotal)
+	require.NoError(t, err)
+
+	// Verify the cache was updated by retrieving the total active balance
+	// which should now return the cached value
+	cachedTotal, err := helpers.TotalActiveBalance(state)
+	require.NoError(t, err)
+	assert.Equal(t, testTotal, cachedTotal, "Cache should return the updated total")
+}

beacon-chain/core/helpers/sync_committee.go

@@ -21,6 +21,39 @@ var (
 	syncCommitteeCache = cache.NewSyncCommittee()
 )
 
+// CurrentPeriodPositions returns committee indices of the current period sync committee for input validators.
+func CurrentPeriodPositions(st state.BeaconState, indices []primitives.ValidatorIndex) ([][]primitives.CommitteeIndex, error) {
+	root, err := SyncPeriodBoundaryRoot(st)
+	if err != nil {
+		return nil, err
+	}
+	pos, err := syncCommitteeCache.CurrentPeriodPositions(root, indices)
+	if errors.Is(err, cache.ErrNonExistingSyncCommitteeKey) {
+		committee, err := st.CurrentSyncCommittee()
+		if err != nil {
+			return nil, err
+		}
+
+		// Fill in the cache on miss.
+		go func() {
+			if err := syncCommitteeCache.UpdatePositionsInCommittee(root, st); err != nil {
+				log.WithError(err).Error("Could not fill sync committee cache on miss")
+			}
+		}()
+
+		pos = make([][]primitives.CommitteeIndex, len(indices))
+		for i, idx := range indices {
+			pubkey := st.PubkeyAtIndex(idx)
+			pos[i] = findSubCommitteeIndices(pubkey[:], committee.Pubkeys)
+		}
+		return pos, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return pos, nil
+}
+
 // IsCurrentPeriodSyncCommittee returns true if the input validator index belongs in the current period sync committee
 // along with the sync committee root.
 // 1. Checks if the public key exists in the sync committee cache

beacon-chain/core/helpers/sync_committee_test.go

@@ -17,6 +17,38 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 )
 
+func TestCurrentPeriodPositions(t *testing.T) {
+	helpers.ClearCache()
+
+	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)
+	syncCommittee := &ethpb.SyncCommittee{
+		Pubkeys: make([][]byte, params.BeaconConfig().SyncCommitteeSize),
+	}
+	for i := 0; i < len(validators); i++ {
+		k := make([]byte, 48)
+		copy(k, strconv.Itoa(i))
+		validators[i] = &ethpb.Validator{
+			PublicKey: k,
+		}
+		syncCommittee.Pubkeys[i] = bytesutil.PadTo(k, 48)
+	}
+	state, err := state_native.InitializeFromProtoAltair(&ethpb.BeaconStateAltair{
+		Validators: validators,
+	})
+	require.NoError(t, err)
+	require.NoError(t, state.SetCurrentSyncCommittee(syncCommittee))
+	require.NoError(t, state.SetNextSyncCommittee(syncCommittee))
+	require.NoError(t, err, helpers.SyncCommitteeCache().UpdatePositionsInCommittee([32]byte{}, state))
+
+	positions, err := helpers.CurrentPeriodPositions(state, []primitives.ValidatorIndex{0, 1})
+	require.NoError(t, err)
+	require.Equal(t, 2, len(positions))
+	require.Equal(t, 1, len(positions[0]))
+	assert.Equal(t, primitives.CommitteeIndex(0), positions[0][0])
+	require.Equal(t, 1, len(positions[1]))
+	assert.Equal(t, primitives.CommitteeIndex(1), positions[1][0])
+}
+
 func TestIsCurrentEpochSyncCommittee_UsingCache(t *testing.T) {
 	helpers.ClearCache()
 
@@ -78,6 +110,7 @@ func TestIsCurrentEpochSyncCommittee_UsingCommittee(t *testing.T) {
 
 func TestIsCurrentEpochSyncCommittee_DoesNotExist(t *testing.T) {
 	helpers.ClearCache()
+	params.SetupTestConfigCleanup(t)
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)
 	syncCommittee := &ethpb.SyncCommittee{
@@ -264,6 +297,7 @@ func TestCurrentEpochSyncSubcommitteeIndices_UsingCommittee(t *testing.T) {
 }
 
 func TestCurrentEpochSyncSubcommitteeIndices_DoesNotExist(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
 	helpers.ClearCache()
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)

beacon-chain/core/helpers/validators.go

@@ -309,23 +309,29 @@ func beaconProposerIndexAtSlotFulu(state state.ReadOnlyBeaconState, slot primiti
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get proposer lookahead")
 	}
+	spe := params.BeaconConfig().SlotsPerEpoch
 	if e == stateEpoch {
-		return lookAhead[slot%params.BeaconConfig().SlotsPerEpoch], nil
+		return lookAhead[slot%spe], nil
 	}
 	// The caller is requesting the proposer for the next epoch
-	return lookAhead[slot%params.BeaconConfig().SlotsPerEpoch+params.BeaconConfig().SlotsPerEpoch], nil
+	return lookAhead[spe+slot%spe], nil
 }
 
 // BeaconProposerIndexAtSlot returns proposer index at the given slot from the
 // point of view of the given state as head state
 func BeaconProposerIndexAtSlot(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot) (primitives.ValidatorIndex, error) {
-	if state.Version() >= version.Fulu {
-		return beaconProposerIndexAtSlotFulu(state, slot)
-	}
 	e := slots.ToEpoch(slot)
+	stateEpoch := slots.ToEpoch(state.Slot())
+	// Even if the state is post Fulu, we may request a past proposer index.
+	if state.Version() >= version.Fulu && e >= params.BeaconConfig().FuluForkEpoch {
+		// We can use the cached lookahead only for the current and the next epoch.
+		if e == stateEpoch || e == stateEpoch+1 {
+			return beaconProposerIndexAtSlotFulu(state, slot)
+		}
+	}
 	// The cache uses the state root of the previous epoch - minimum_seed_lookahead last slot as key. (e.g. Starting epoch 1, slot 32, the key would be block root at slot 31)
-	// For simplicity, the node will skip caching of genesis epoch.
-	if e > params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
+	// For simplicity, the node will skip caching of genesis epoch. If the passed state has not yet reached this slot then we do not check the cache.
+	if e <= stateEpoch && e > params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
 		s, err := slots.EpochEnd(e - 1)
 		if err != nil {
 			return 0, err

beacon-chain/core/helpers/validators_test.go

@@ -1161,6 +1161,10 @@ func TestValidatorMaxEffectiveBalance(t *testing.T) {
 }
 
 func TestBeaconProposerIndexAtSlotFulu(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.FuluForkEpoch = 1
+	params.OverrideBeaconConfig(cfg)
 	lookahead := make([]uint64, 64)
 	lookahead[0] = 15
 	lookahead[1] = 16
@@ -1180,8 +1184,4 @@ func TestBeaconProposerIndexAtSlotFulu(t *testing.T) {
 	idx, err = helpers.BeaconProposerIndexAtSlot(t.Context(), st, 130)
 	require.NoError(t, err)
 	require.Equal(t, primitives.ValidatorIndex(42), idx)
-	_, err = helpers.BeaconProposerIndexAtSlot(t.Context(), st, 95)
-	require.ErrorContains(t, "slot 95 is not in the current epoch 3 or the next epoch", err)
-	_, err = helpers.BeaconProposerIndexAtSlot(t.Context(), st, 160)
-	require.ErrorContains(t, "slot 160 is not in the current epoch 3 or the next epoch", err)
 }

beacon-chain/core/helpers/weak_subjectivity.go

@@ -206,9 +206,9 @@ func ParseWeakSubjectivityInputString(wsCheckpointString string) (*v1alpha1.Chec
 // MinEpochsForBlockRequests computes the number of epochs of block history that we need to maintain,
 // relative to the current epoch, per the p2p specs. This is used to compute the slot where backfill is complete.
 // value defined:
-// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#configuration
+// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#configuration
 // MIN_VALIDATOR_WITHDRAWABILITY_DELAY + CHURN_LIMIT_QUOTIENT // 2 (= 33024, ~5 months)
-// detailed rationale: https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
+// detailed rationale: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
 func MinEpochsForBlockRequests() primitives.Epoch {
 	return params.BeaconConfig().MinValidatorWithdrawabilityDelay +
 		primitives.Epoch(params.BeaconConfig().ChurnLimitQuotient/2)

beacon-chain/core/helpers/weak_subjectivity_test.go

@@ -292,7 +292,7 @@ func TestMinEpochsForBlockRequests(t *testing.T) {
 	params.SetActiveTestCleanup(t, params.MainnetConfig())
 	var expected primitives.Epoch = 33024
 	// expected value of 33024 via spec commentary:
-	// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
 	//	MIN_EPOCHS_FOR_BLOCK_REQUESTS is calculated using the arithmetic from compute_weak_subjectivity_period found in the weak subjectivity guide. Specifically to find this max epoch range, we use the worst case event of a very large validator size (>= MIN_PER_EPOCH_CHURN_LIMIT * CHURN_LIMIT_QUOTIENT).
 	//
 	//	MIN_EPOCHS_FOR_BLOCK_REQUESTS = (

beacon-chain/core/light-client/store.go

@@ -1,77 +0,0 @@
-package light_client
-
-import (
-	"context"
-	"sync"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/iface"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
-	"github.com/pkg/errors"
-)
-
-var ErrLightClientBootstrapNotFound = errors.New("light client bootstrap not found")
-
-type Store struct {
-	mu sync.RWMutex
-
-	beaconDB             iface.HeadAccessDatabase
-	lastFinalityUpdate   interfaces.LightClientFinalityUpdate
-	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate
-}
-
-func NewLightClientStore(db iface.HeadAccessDatabase) *Store {
-	return &Store{
-		beaconDB: db,
-	}
-}
-
-func (s *Store) LightClientBootstrap(ctx context.Context, blockRoot [32]byte) (interfaces.LightClientBootstrap, error) {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-
-	// Fetch the light client bootstrap from the database
-	bootstrap, err := s.beaconDB.LightClientBootstrap(ctx, blockRoot[:])
-	if err != nil {
-		return nil, err
-	}
-	if bootstrap == nil { // not found
-		return nil, ErrLightClientBootstrapNotFound
-	}
-
-	return bootstrap, nil
-}
-
-func (s *Store) SaveLightClientBootstrap(ctx context.Context, blockRoot [32]byte, bootstrap interfaces.LightClientBootstrap) error {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	// Save the light client bootstrap to the database
-	if err := s.beaconDB.SaveLightClientBootstrap(ctx, blockRoot[:], bootstrap); err != nil {
-		return err
-	}
-	return nil
-}
-
-func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	s.lastFinalityUpdate = update
-}
-
-func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-	return s.lastFinalityUpdate
-}
-
-func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate) {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	s.lastOptimisticUpdate = update
-}
-
-func (s *Store) LastOptimisticUpdate() interfaces.LightClientOptimisticUpdate {
-	s.mu.RLock()
-	defer s.mu.RUnlock()
-	return s.lastOptimisticUpdate
-}

beacon-chain/core/light-client/store_test.go

@@ -1,68 +0,0 @@
-package light_client_test
-
-import (
-	"testing"
-
-	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
-	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
-)
-
-func TestLightClientStore(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	cfg := params.BeaconConfig()
-	cfg.AltairForkEpoch = 1
-	cfg.BellatrixForkEpoch = 2
-	cfg.CapellaForkEpoch = 3
-	cfg.DenebForkEpoch = 4
-	cfg.ElectraForkEpoch = 5
-	params.OverrideBeaconConfig(cfg)
-
-	// Initialize the light client store
-	lcStore := &lightClient.Store{}
-
-	// Create test light client updates for Capella and Deneb
-	lCapella := util.NewTestLightClient(t, version.Capella)
-	opUpdateCapella, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lCapella.Ctx, lCapella.State.Slot(), lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock)
-	require.NoError(t, err)
-	require.NotNil(t, opUpdateCapella, "OptimisticUpdateCapella is nil")
-	finUpdateCapella, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(lCapella.Ctx, lCapella.State.Slot(), lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock, lCapella.FinalizedBlock)
-	require.NoError(t, err)
-	require.NotNil(t, finUpdateCapella, "FinalityUpdateCapella is nil")
-
-	lDeneb := util.NewTestLightClient(t, version.Deneb)
-	opUpdateDeneb, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State.Slot(), lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock)
-	require.NoError(t, err)
-	require.NotNil(t, opUpdateDeneb, "OptimisticUpdateDeneb is nil")
-	finUpdateDeneb, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State.Slot(), lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock, lDeneb.FinalizedBlock)
-	require.NoError(t, err)
-	require.NotNil(t, finUpdateDeneb, "FinalityUpdateDeneb is nil")
-
-	// Initially the store should have nil values for both updates
-	require.IsNil(t, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should be nil")
-	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
-
-	// Set and get finality with Capella update. Optimistic update should be nil
-	lcStore.SetLastFinalityUpdate(finUpdateCapella)
-	require.Equal(t, finUpdateCapella, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
-	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
-
-	// Set and get optimistic with Capella update. Finality update should be Capella
-	lcStore.SetLastOptimisticUpdate(opUpdateCapella)
-	require.Equal(t, opUpdateCapella, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate is wrong")
-	require.Equal(t, finUpdateCapella, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
-
-	// Set and get finality and optimistic with Deneb update
-	lcStore.SetLastFinalityUpdate(finUpdateDeneb)
-	lcStore.SetLastOptimisticUpdate(opUpdateDeneb)
-	require.Equal(t, finUpdateDeneb, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
-	require.Equal(t, opUpdateDeneb, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate is wrong")
-
-	// Set and get finality and optimistic with nil update
-	lcStore.SetLastFinalityUpdate(nil)
-	lcStore.SetLastOptimisticUpdate(nil)
-	require.IsNil(t, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should be nil")
-	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
-}

beacon-chain/core/peerdas/BUILD.bazel

@@ -16,15 +16,14 @@ go_library(
     deps = [
         "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/state:go_default_library",
-        "//cmd/beacon-chain/flags:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
-        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//container/trie:go_default_library",
         "//crypto/hash:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
@@ -53,7 +52,6 @@ go_test(
         ":go_default_library",
         "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
-        "//cmd/beacon-chain/flags:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

beacon-chain/core/peerdas/das_core.go

@@ -4,15 +4,10 @@ import (
 	"encoding/binary"
 	"math"
 	"slices"
-	"time"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/holiman/uint256"
 	"github.com/pkg/errors"
@@ -20,38 +15,28 @@ import (
 
 var (
 	// Custom errors
-	ErrCustodyGroupTooLarge               = errors.New("custody group too large")
-	ErrCustodyGroupCountTooLarge          = errors.New("custody group count too large")
-	ErrSizeMismatch                       = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
-	ErrNotEnoughDataColumnSidecars        = errors.New("not enough columns")
-	ErrDataColumnSidecarsNotSortedByIndex = errors.New("data column sidecars are not sorted by index")
-	errWrongComputedCustodyGroupCount     = errors.New("wrong computed custody group count, should never happen")
+	ErrCustodyGroupTooLarge           = errors.New("custody group too large")
+	ErrCustodyGroupCountTooLarge      = errors.New("custody group count too large")
+	errWrongComputedCustodyGroupCount = errors.New("wrong computed custody group count, should never happen")
 
 	// maxUint256 is the maximum value of an uint256.
 	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
 )
 
-type CustodyType int
-
-const (
-	Target CustodyType = iota
-	Actual
-)
-
 // CustodyGroups computes the custody groups the node should participate in for custody.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#get_custody_groups
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#get_custody_groups
 func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error) {
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
 
 	// Check if the custody group count is larger than the number of custody groups.
-	if custodyGroupCount > numberOfCustodyGroup {
+	if custodyGroupCount > numberOfCustodyGroups {
 		return nil, ErrCustodyGroupCountTooLarge
 	}
 
 	// Shortcut if all custody groups are needed.
-	if custodyGroupCount == numberOfCustodyGroup {
-		custodyGroups := make([]uint64, 0, numberOfCustodyGroup)
-		for i := range numberOfCustodyGroup {
+	if custodyGroupCount == numberOfCustodyGroups {
+		custodyGroups := make([]uint64, 0, numberOfCustodyGroups)
+		for i := range numberOfCustodyGroups {
 			custodyGroups = append(custodyGroups, i)
 		}
 
@@ -73,7 +58,7 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 		hashedCurrentId := hash.Hash(currentIdBytesLittleEndian)
 
 		// Get the custody group ID.
-		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroup
+		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroups
 
 		// Add the custody group to the map.
 		if !custodyGroupsMap[custodyGroup] {
@@ -88,9 +73,6 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 			// Increment the current ID.
 			currentId.Add(currentId, one)
 		}
-
-		// Sort the custody groups.
-		slices.Sort[[]uint64](custodyGroups)
 	}
 
 	// Final check.
@@ -98,70 +80,35 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 		return nil, errWrongComputedCustodyGroupCount
 	}
 
+	// Sort the custody groups.
+	slices.Sort[[]uint64](custodyGroups)
+
 	return custodyGroups, nil
 }
 
 // ComputeColumnsForCustodyGroup computes the columns for a given custody group.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#compute_columns_for_custody_group
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#compute_columns_for_custody_group
 func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 	beaconConfig := params.BeaconConfig()
-	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
 
-	if custodyGroup >= numberOfCustodyGroup {
+	if custodyGroup >= numberOfCustodyGroups {
 		return nil, ErrCustodyGroupTooLarge
 	}
 
 	numberOfColumns := beaconConfig.NumberOfColumns
 
-	columnsPerGroup := numberOfColumns / numberOfCustodyGroup
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroups
 
 	columns := make([]uint64, 0, columnsPerGroup)
 	for i := range columnsPerGroup {
-		column := numberOfCustodyGroup*i + custodyGroup
+		column := numberOfCustodyGroups*i + custodyGroup
 		columns = append(columns, column)
 	}
 
 	return columns, nil
 }
 
-// DataColumnSidecars computes the data column sidecars from the signed block, cells and cell proofs.
-// The returned value contains pointers to function parameters.
-// (If the caller alterates `cellsAndProofs` afterwards, the returned value will be modified as well.)
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.3/specs/fulu/das-core.md#get_data_column_sidecars
-func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
-	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
-		return nil, nil
-	}
-
-	block := signedBlock.Block()
-	blockBody := block.Body()
-	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
-	if err != nil {
-		return nil, errors.Wrap(err, "blob KZG commitments")
-	}
-
-	if len(blobKzgCommitments) != len(cellsAndProofs) {
-		return nil, ErrSizeMismatch
-	}
-
-	signedBlockHeader, err := signedBlock.Header()
-	if err != nil {
-		return nil, errors.Wrap(err, "signed block header")
-	}
-
-	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
-	if err != nil {
-		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
-	}
-
-	dataColumnSidecars, err := dataColumnsSidecars(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
-	if err != nil {
-		return nil, errors.Wrap(err, "data column sidecars")
-	}
-
-	return dataColumnSidecars, nil
-}
-
 // ComputeCustodyGroupForColumn computes the custody group for a given column.
 // It is the reciprocal function of ComputeColumnsForCustodyGroup.
 func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
@@ -176,19 +123,6 @@ func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
 	return columnIndex % numberOfCustodyGroups, nil
 }
 
-// CustodyGroupSamplingSize returns the number of custody groups the node should sample from.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#custody-sampling
-func (custodyInfo *CustodyInfo) CustodyGroupSamplingSize(ct CustodyType) uint64 {
-	custodyGroupCount := custodyInfo.TargetGroupCount.Get()
-
-	if ct == Actual {
-		custodyGroupCount = custodyInfo.ActualGroupCount()
-	}
-
-	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
-	return max(samplesPerSlot, custodyGroupCount)
-}
-
 // CustodyColumns computes the custody columns from the custody groups.
 func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
 	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
@@ -214,63 +148,3 @@ func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
 
 	return columns, nil
 }
-
-// dataColumnsSidecars computes the data column sidecars from the signed block header, the blob KZG commiments,
-// the KZG commitment includion proofs and cells and cell proofs.
-// The returned value contains pointers to function parameters.
-// (If the caller alterates input parameters afterwards, the returned value will be modified as well.)
-func dataColumnsSidecars(
-	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
-	blobKzgCommitments [][]byte,
-	kzgCommitmentsInclusionProof [][]byte,
-	cellsAndProofs []kzg.CellsAndProofs,
-) ([]*ethpb.DataColumnSidecar, error) {
-	start := time.Now()
-	if len(blobKzgCommitments) != len(cellsAndProofs) {
-		return nil, ErrSizeMismatch
-	}
-
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	blobsCount := len(cellsAndProofs)
-	sidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
-	for columnIndex := range numberOfColumns {
-		column := make([]kzg.Cell, 0, blobsCount)
-		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
-
-		for rowIndex := range blobsCount {
-			cellsForRow := cellsAndProofs[rowIndex].Cells
-			proofsForRow := cellsAndProofs[rowIndex].Proofs
-
-			cell := cellsForRow[columnIndex]
-			column = append(column, cell)
-
-			kzgProof := proofsForRow[columnIndex]
-			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
-		}
-
-		columnBytes := make([][]byte, 0, blobsCount)
-		for i := range column {
-			columnBytes = append(columnBytes, column[i][:])
-		}
-
-		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
-		for _, kzgProof := range kzgProofOfColumn {
-			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, kzgProof[:])
-		}
-
-		sidecar := &ethpb.DataColumnSidecar{
-			Index:                        columnIndex,
-			Column:                       columnBytes,
-			KzgCommitments:               blobKzgCommitments,
-			KzgProofs:                    kzgProofOfColumnBytes,
-			SignedBlockHeader:            signedBlockHeader,
-			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
-		}
-
-		sidecars = append(sidecars, sidecar)
-	}
-
-	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
-	return sidecars, nil
-}

beacon-chain/core/peerdas/das_core_test.go

@@ -3,13 +3,9 @@ package peerdas_test
 import (
 	"testing"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 )
 
@@ -17,8 +13,8 @@ func TestCustodyGroups(t *testing.T) {
 	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
 	// --------------------------------------------
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
-	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroup+1)
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroups+1)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupCountTooLarge)
 }
 
@@ -26,49 +22,11 @@ func TestComputeColumnsForCustodyGroup(t *testing.T) {
 	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
 	// --------------------------------------------
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
-	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroup)
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroups)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
 }
 
-func TestDataColumnSidecars(t *testing.T) {
-	t.Run("nil signed block", func(t *testing.T) {
-		var expected []*ethpb.DataColumnSidecar = nil
-		actual, err := peerdas.DataColumnSidecars(nil, []kzg.CellsAndProofs{})
-		require.NoError(t, err)
-
-		require.DeepSSZEqual(t, expected, actual)
-	})
-
-	t.Run("empty cells and proofs", func(t *testing.T) {
-		// Create a protobuf signed beacon block.
-		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
-
-		// Create a signed beacon block from the protobuf.
-		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
-		require.NoError(t, err)
-
-		actual, err := peerdas.DataColumnSidecars(signedBeaconBlock, []kzg.CellsAndProofs{})
-		require.NoError(t, err)
-		require.IsNil(t, actual)
-	})
-
-	t.Run("sizes mismatch", func(t *testing.T) {
-		// Create a protobuf signed beacon block.
-		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
-
-		// Create a signed beacon block from the protobuf.
-		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
-		require.NoError(t, err)
-
-		// Create cells and proofs.
-		cellsAndProofs := make([]kzg.CellsAndProofs, 1)
-
-		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
-		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
-	})
-}
-
 func TestComputeCustodyGroupForColumn(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig()
@@ -104,62 +62,6 @@ func TestComputeCustodyGroupForColumn(t *testing.T) {
 	})
 }
 
-func TestCustodyGroupSamplingSize(t *testing.T) {
-	testCases := []struct {
-		name                         string
-		custodyType                  peerdas.CustodyType
-		validatorsCustodyRequirement uint64
-		toAdvertiseCustodyGroupCount uint64
-		expected                     uint64
-	}{
-		{
-			name:                         "target, lower than samples per slot",
-			custodyType:                  peerdas.Target,
-			validatorsCustodyRequirement: 2,
-			expected:                     8,
-		},
-		{
-			name:                         "target, higher than samples per slot",
-			custodyType:                  peerdas.Target,
-			validatorsCustodyRequirement: 100,
-			expected:                     100,
-		},
-		{
-			name:                         "actual, lower than samples per slot",
-			custodyType:                  peerdas.Actual,
-			validatorsCustodyRequirement: 3,
-			toAdvertiseCustodyGroupCount: 4,
-			expected:                     8,
-		},
-		{
-			name:                         "actual, higher than samples per slot",
-			custodyType:                  peerdas.Actual,
-			validatorsCustodyRequirement: 100,
-			toAdvertiseCustodyGroupCount: 101,
-			expected:                     100,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			// Create a custody info.
-			custodyInfo := peerdas.CustodyInfo{}
-
-			// Set the validators custody requirement for target custody group count.
-			custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(tc.validatorsCustodyRequirement)
-
-			// Set the to advertise custody group count.
-			custodyInfo.ToAdvertiseGroupCount.Set(tc.toAdvertiseCustodyGroupCount)
-
-			// Compute the custody group sampling size.
-			actual := custodyInfo.CustodyGroupSamplingSize(tc.custodyType)
-
-			// Check the result.
-			require.Equal(t, tc.expected, actual)
-		})
-	}
-}
-
 func TestCustodyColumns(t *testing.T) {
 	t.Run("group too large", func(t *testing.T) {
 		_, err := peerdas.CustodyColumns([]uint64{1_000_000})

beacon-chain/core/peerdas/info.go

@@ -4,45 +4,17 @@ import (
 	"encoding/binary"
 	"sync"
 
-	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
-	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	lru "github.com/hashicorp/golang-lru"
 	"github.com/pkg/errors"
 )
 
 // info contains all useful peerDAS related information regarding a peer.
-type (
-	info struct {
-		CustodyGroups      map[uint64]bool
-		CustodyColumns     map[uint64]bool
-		DataColumnsSubnets map[uint64]bool
-	}
-
-	targetCustodyGroupCount struct {
-		mut                          sync.RWMutex
-		validatorsCustodyRequirement uint64
-	}
-
-	toAdverstiseCustodyGroupCount struct {
-		mut   sync.RWMutex
-		value uint64
-	}
-
-	CustodyInfo struct {
-		// Mut is a mutex to be used by caller to ensure neither
-		// TargetCustodyGroupCount nor ToAdvertiseCustodyGroupCount are being modified.
-		// (This is not necessary to use this mutex for any data protection.)
-		Mut sync.RWMutex
-
-		// TargetGroupCount represents the target number of custody groups we should custody
-		// regarding the validators we are tracking.
-		TargetGroupCount targetCustodyGroupCount
-
-		// ToAdvertiseGroupCount represents the number of custody groups to advertise to the network.
-		ToAdvertiseGroupCount toAdverstiseCustodyGroupCount
-	}
-)
+type info struct {
+	CustodyGroups      map[uint64]bool
+	CustodyColumns     map[uint64]bool
+	DataColumnsSubnets map[uint64]bool
+}
 
 const (
 	nodeInfoCacheSize   = 200
@@ -109,61 +81,6 @@ func Info(nodeID enode.ID, custodyGroupCount uint64) (*info, bool, error) {
 	return result, false, nil
 }
 
-// ActualGroupCount returns the actual custody group count.
-func (custodyInfo *CustodyInfo) ActualGroupCount() uint64 {
-	return min(custodyInfo.TargetGroupCount.Get(), custodyInfo.ToAdvertiseGroupCount.Get())
-}
-
-// CustodyGroupCount returns the number of groups we should participate in for custody.
-func (tcgc *targetCustodyGroupCount) Get() uint64 {
-	// If subscribed to all subnets, return the number of custody groups.
-	if flags.Get().SubscribeAllDataSubnets {
-		return params.BeaconConfig().NumberOfCustodyGroups
-	}
-
-	tcgc.mut.RLock()
-	defer tcgc.mut.RUnlock()
-
-	// If no validators are tracked, return the default custody requirement.
-	if tcgc.validatorsCustodyRequirement == 0 {
-		return params.BeaconConfig().CustodyRequirement
-	}
-
-	// Return the validators custody requirement.
-	return tcgc.validatorsCustodyRequirement
-}
-
-// setValidatorsCustodyRequirement sets the validators custody requirement.
-func (tcgc *targetCustodyGroupCount) SetValidatorsCustodyRequirement(value uint64) {
-	tcgc.mut.Lock()
-	defer tcgc.mut.Unlock()
-
-	tcgc.validatorsCustodyRequirement = value
-}
-
-// Get returns the to advertise custody group count.
-func (tacgc *toAdverstiseCustodyGroupCount) Get() uint64 {
-	// If subscribed to all subnets, return the number of custody groups.
-	if flags.Get().SubscribeAllDataSubnets {
-		return params.BeaconConfig().NumberOfCustodyGroups
-	}
-
-	custodyRequirement := params.BeaconConfig().CustodyRequirement
-
-	tacgc.mut.RLock()
-	defer tacgc.mut.RUnlock()
-
-	return max(tacgc.value, custodyRequirement)
-}
-
-// Set sets the to advertise custody group count.
-func (tacgc *toAdverstiseCustodyGroupCount) Set(value uint64) {
-	tacgc.mut.Lock()
-	defer tacgc.mut.Unlock()
-
-	tacgc.value = value
-}
-
 // createInfoCacheIfNeeded creates a new cache if it doesn't exist.
 func createInfoCacheIfNeeded() error {
 	nodeInfoCacheMut.Lock()

beacon-chain/core/peerdas/info_test.go

@@ -4,7 +4,6 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
-	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 )
@@ -26,108 +25,3 @@ func TestInfo(t *testing.T) {
 		require.DeepEqual(t, expectedDataColumnsSubnets, actual.DataColumnsSubnets)
 	}
 }
-
-func TestTargetCustodyGroupCount(t *testing.T) {
-	testCases := []struct {
-		name                         string
-		subscribeToAllColumns        bool
-		validatorsCustodyRequirement uint64
-		expected                     uint64
-	}{
-		{
-			name:                         "subscribed to all data subnets",
-			subscribeToAllColumns:        true,
-			validatorsCustodyRequirement: 100,
-			expected:                     128,
-		},
-		{
-			name:                         "no validators attached",
-			subscribeToAllColumns:        false,
-			validatorsCustodyRequirement: 0,
-			expected:                     4,
-		},
-		{
-			name:                         "some validators attached",
-			subscribeToAllColumns:        false,
-			validatorsCustodyRequirement: 100,
-			expected:                     100,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			// Subscribe to all subnets if needed.
-			if tc.subscribeToAllColumns {
-				resetFlags := flags.Get()
-				gFlags := new(flags.GlobalFlags)
-				gFlags.SubscribeAllDataSubnets = true
-				flags.Init(gFlags)
-				defer flags.Init(resetFlags)
-			}
-
-			var custodyInfo peerdas.CustodyInfo
-
-			// Set the validators custody requirement.
-			custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(tc.validatorsCustodyRequirement)
-
-			// Get the target custody group count.
-			actual := custodyInfo.TargetGroupCount.Get()
-
-			// Compare the expected and actual values.
-			require.Equal(t, tc.expected, actual)
-		})
-	}
-}
-
-func TestToAdvertiseCustodyGroupCount(t *testing.T) {
-	testCases := []struct {
-		name                         string
-		subscribeToAllColumns        bool
-		toAdvertiseCustodyGroupCount uint64
-		expected                     uint64
-	}{
-		{
-			name:                         "subscribed to all subnets",
-			subscribeToAllColumns:        true,
-			toAdvertiseCustodyGroupCount: 100,
-			expected:                     128,
-		},
-		{
-			name:                         "higher than custody requirement",
-			subscribeToAllColumns:        false,
-			toAdvertiseCustodyGroupCount: 100,
-			expected:                     100,
-		},
-		{
-			name:                         "lower than custody requirement",
-			subscribeToAllColumns:        false,
-			toAdvertiseCustodyGroupCount: 1,
-			expected:                     4,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			// Subscribe to all subnets if needed.
-			if tc.subscribeToAllColumns {
-				resetFlags := flags.Get()
-				gFlags := new(flags.GlobalFlags)
-				gFlags.SubscribeAllDataSubnets = true
-				flags.Init(gFlags)
-				defer flags.Init(resetFlags)
-			}
-
-			// Create a custody info.
-			var custodyInfo peerdas.CustodyInfo
-
-			// Set the to advertise custody group count.
-			custodyInfo.ToAdvertiseGroupCount.Set(tc.toAdvertiseCustodyGroupCount)
-
-			// Get the to advertise custody group count.
-			actual := custodyInfo.ToAdvertiseGroupCount.Get()
-
-			// Compare the expected and actual values.
-			require.Equal(t, tc.expected, actual)
-		})
-	}
-}

beacon-chain/core/peerdas/p2p_interface.go

@@ -10,10 +10,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-const (
-	CustodyGroupCountEnrKey = "cgc"
-	kzgPosition             = 11 // The index of the KZG commitment list in the Body
-)
+const kzgPosition = 11 // The index of the KZG commitment list in the Body
 
 var (
 	ErrIndexTooLarge               = errors.New("column index is larger than the specified columns count")
@@ -27,13 +24,13 @@ var (
 	ErrCannotLoadCustodyGroupCount = errors.New("cannot load the custody group count from peer")
 )
 
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#custody-group-count
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#custody-group-count
 type Cgc uint64
 
-func (Cgc) ENRKey() string { return CustodyGroupCountEnrKey }
+func (Cgc) ENRKey() string { return params.BeaconNetworkConfig().CustodyGroupCountKey }
 
 // VerifyDataColumnSidecar verifies if the data column sidecar is valid.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#verify_data_column_sidecar
 func VerifyDataColumnSidecar(sidecar blocks.RODataColumn) error {
 	// The sidecar index must be within the valid range.
 	numberOfColumns := params.BeaconConfig().NumberOfColumns
@@ -60,7 +57,7 @@ func VerifyDataColumnSidecar(sidecar blocks.RODataColumn) error {
 // while we are verifying all the KZG proofs from multiple sidecars in a batch.
 // This is done to improve performance since the internal KZG library is way more
 // efficient when verifying in batch.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar_kzg_proofs
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#verify_data_column_sidecar_kzg_proofs
 func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) error {
 	// Compute the total count.
 	count := 0
@@ -96,7 +93,7 @@ func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) error {
 }
 
 // VerifyDataColumnSidecarInclusionProof verifies if the given KZG commitments included in the given beacon block.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar_inclusion_proof
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#verify_data_column_sidecar_inclusion_proof
 func VerifyDataColumnSidecarInclusionProof(sidecar blocks.RODataColumn) error {
 	if sidecar.SignedBlockHeader == nil || sidecar.SignedBlockHeader.Header == nil {
 		return ErrNilBlockHeader
@@ -128,7 +125,7 @@ func VerifyDataColumnSidecarInclusionProof(sidecar blocks.RODataColumn) error {
 }
 
 // ComputeSubnetForDataColumnSidecar computes the subnet for a data column sidecar.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
 func ComputeSubnetForDataColumnSidecar(columnIndex uint64) uint64 {
 	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
 	return columnIndex % dataColumnSidecarSubnetCount

beacon-chain/core/peerdas/p2p_interface_test.go

@@ -63,17 +63,14 @@ func TestVerifyDataColumnSidecarKZGProofs(t *testing.T) {
 	t.Run("invalid proof", func(t *testing.T) {
 		sidecars := generateRandomSidecars(t, seed, blobCount)
 		sidecars[0].Column[0][0]++ // It is OK to overflow
-		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
 
-		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
 		require.ErrorIs(t, err, peerdas.ErrInvalidKZGProof)
 	})
 
 	t.Run("nominal", func(t *testing.T) {
 		sidecars := generateRandomSidecars(t, seed, blobCount)
-		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
-
-		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
 		require.NoError(t, err)
 	})
 }
@@ -256,9 +253,8 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_SameCommitments_NoBatch(b *testin
 	for i := range int64(b.N) {
 		// Generate new random sidecars to ensure the KZG backend does not cache anything.
 		sidecars := generateRandomSidecars(b, i, blobCount)
-		roDataColumnSidecars := generateRODataColumnSidecars(b, sidecars)
 
-		for _, sidecar := range roDataColumnSidecars {
+		for _, sidecar := range sidecars {
 			sidecars := []blocks.RODataColumn{sidecar}
 			b.StartTimer()
 			err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
@@ -282,7 +278,7 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch(b *testing.
 			b.ResetTimer()
 
 			for j := range int64(b.N) {
-				allSidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
+				allSidecars := make([]blocks.RODataColumn, 0, numberOfColumns)
 				for k := int64(0); k < numberOfColumns; k += columnsCount {
 					// Use different seeds to generate different blobs/commitments
 					seed := int64(b.N*i) + numberOfColumns*j + blobCount*k
@@ -292,10 +288,8 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch(b *testing.
 					allSidecars = append(allSidecars, sidecars[k:k+columnsCount]...)
 				}
 
-				roDataColumnSidecars := generateRODataColumnSidecars(b, allSidecars)
-
 				b.StartTimer()
-				err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+				err := peerdas.VerifyDataColumnsSidecarKZGProofs(allSidecars)
 				b.StopTimer()
 				require.NoError(b, err)
 			}
@@ -323,8 +317,7 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch4(b *testing
 		for j := range int64(batchCount) {
 			// Use different seeds to generate different blobs/commitments
 			sidecars := generateRandomSidecars(b, int64(batchCount)*i+j*blobCount, blobCount)
-			roDataColumnSidecars := generateRODataColumnSidecars(b, sidecars[:columnsCount])
-			allSidecars = append(allSidecars, roDataColumnSidecars)
+			allSidecars = append(allSidecars, sidecars)
 		}
 
 		for _, sidecars := range allSidecars {
@@ -358,7 +351,7 @@ func createTestSidecar(t *testing.T, index uint64, column, kzgCommitments, kzgPr
 	return roSidecar
 }
 
-func generateRandomSidecars(t testing.TB, seed, blobCount int64) []*ethpb.DataColumnSidecar {
+func generateRandomSidecars(t testing.TB, seed, blobCount int64) []blocks.RODataColumn {
 	dbBlock := util.NewBeaconBlockDeneb()
 
 	commitments := make([][]byte, 0, blobCount)
@@ -379,20 +372,10 @@ func generateRandomSidecars(t testing.TB, seed, blobCount int64) []*ethpb.DataCo
 	require.NoError(t, err)
 
 	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
-	sidecars, err := peerdas.DataColumnSidecars(sBlock, cellsAndProofs)
+	rob, err := blocks.NewROBlock(sBlock)
+	require.NoError(t, err)
+	sidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
 	require.NoError(t, err)
 
 	return sidecars
 }
-
-func generateRODataColumnSidecars(t testing.TB, sidecars []*ethpb.DataColumnSidecar) []blocks.RODataColumn {
-	roDataColumnSidecars := make([]blocks.RODataColumn, 0, len(sidecars))
-	for _, sidecar := range sidecars {
-		roCol, err := blocks.NewRODataColumn(sidecar)
-		require.NoError(t, err)
-
-		roDataColumnSidecars = append(roDataColumnSidecars, roCol)
-	}
-
-	return roDataColumnSidecars
-}

beacon-chain/core/peerdas/reconstruction.go

@@ -5,7 +5,7 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	pb "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
@@ -16,10 +16,11 @@ var (
 	ErrBlobIndexTooHigh         = errors.New("blob index is too high")
 	ErrBlockRootMismatch        = errors.New("block root mismatch")
 	ErrBlobsCellsProofsMismatch = errors.New("blobs and cells proofs mismatch")
+	ErrNilBlobAndProof          = errors.New("nil blob and proof")
 )
 
-// MinimumColumnsCountToReconstruct return the minimum number of columns needed to proceed to a reconstruction.
-func MinimumColumnsCountToReconstruct() uint64 {
+// MinimumColumnCountToReconstruct return the minimum number of columns needed to proceed to a reconstruction.
+func MinimumColumnCountToReconstruct() uint64 {
 	// If the number of columns is odd, then we need total / 2 + 1 columns to reconstruct.
 	// If the number of columns is even, then we need total / 2 columns to reconstruct.
 	return (params.BeaconConfig().NumberOfColumns + 1) / 2
@@ -28,19 +29,19 @@ func MinimumColumnsCountToReconstruct() uint64 {
 // ReconstructDataColumnSidecars reconstructs all the data column sidecars from the given input data column sidecars.
 // All input sidecars must be committed to the same block.
 // `inVerifiedRoSidecars` should contain enough (unique) sidecars to reconstruct the missing columns.
-func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataColumn) ([]blocks.VerifiedRODataColumn, error) {
+func ReconstructDataColumnSidecars(verifiedRoSidecars []blocks.VerifiedRODataColumn) ([]blocks.VerifiedRODataColumn, error) {
 	// Check if there is at least one input sidecar.
-	if len(inVerifiedRoSidecars) == 0 {
+	if len(verifiedRoSidecars) == 0 {
 		return nil, ErrNotEnoughDataColumnSidecars
 	}
 
 	// Safely retrieve the first sidecar as a reference.
-	referenceSidecar := inVerifiedRoSidecars[0]
+	referenceSidecar := verifiedRoSidecars[0]
 
 	// Check if all columns have the same length and are commmitted to the same block.
 	blobCount := len(referenceSidecar.Column)
 	blockRoot := referenceSidecar.BlockRoot()
-	for _, sidecar := range inVerifiedRoSidecars[1:] {
+	for _, sidecar := range verifiedRoSidecars[1:] {
 		if len(sidecar.Column) != blobCount {
 			return nil, ErrColumnLengthsDiffer
 		}
@@ -51,23 +52,17 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 	}
 
 	// Deduplicate sidecars.
-	sidecarByIndex := make(map[uint64]blocks.VerifiedRODataColumn, len(inVerifiedRoSidecars))
-	for _, inVerifiedRoSidecar := range inVerifiedRoSidecars {
+	sidecarByIndex := make(map[uint64]blocks.VerifiedRODataColumn, len(verifiedRoSidecars))
+	for _, inVerifiedRoSidecar := range verifiedRoSidecars {
 		sidecarByIndex[inVerifiedRoSidecar.Index] = inVerifiedRoSidecar
 	}
 
 	// Check if there is enough sidecars to reconstruct the missing columns.
 	sidecarCount := len(sidecarByIndex)
-	if uint64(sidecarCount) < MinimumColumnsCountToReconstruct() {
+	if uint64(sidecarCount) < MinimumColumnCountToReconstruct() {
 		return nil, ErrNotEnoughDataColumnSidecars
 	}
 
-	// Sidecars are verified and are committed to the same block.
-	// All signed block headers, KZG commitments, and inclusion proofs are the same.
-	signedBlockHeader := referenceSidecar.SignedBlockHeader
-	kzgCommitments := referenceSidecar.KzgCommitments
-	kzgCommitmentsInclusionProof := referenceSidecar.KzgCommitmentsInclusionProof
-
 	// Recover cells and compute proofs in parallel.
 	var wg errgroup.Group
 	cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
@@ -100,78 +95,20 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 		return nil, errors.Wrap(err, "wait for RecoverCellsAndKZGProofs")
 	}
 
-	outSidecars, err := dataColumnsSidecars(signedBlockHeader, kzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	outSidecars, err := DataColumnSidecars(cellsAndProofs, PopulateFromSidecar(referenceSidecar))
 	if err != nil {
 		return nil, errors.Wrap(err, "data column sidecars from items")
 	}
 
 	// Input sidecars are verified, and we reconstructed ourselves the missing sidecars.
 	// As a consequence, reconstructed sidecars are also verified.
-	outVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(outSidecars))
+	reconstructedVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(outSidecars))
 	for _, sidecar := range outSidecars {
-		roSidecar, err := blocks.NewRODataColumnWithRoot(sidecar, blockRoot)
-		if err != nil {
-			return nil, errors.Wrap(err, "new RO data column with root")
-		}
-
-		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
-		outVerifiedRoSidecars = append(outVerifiedRoSidecars, verifiedRoSidecar)
+		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(sidecar)
+		reconstructedVerifiedRoSidecars = append(reconstructedVerifiedRoSidecars, verifiedRoSidecar)
 	}
 
-	return outVerifiedRoSidecars, nil
-}
-
-// ConstructDataColumnSidecars constructs data column sidecars from a block, (un-extended) blobs and
-// cell proofs corresponding the extended blobs. The main purpose of this function is to
-// construct data columns sidecars from data obtained from the execution client via:
-// - `engine_getBlobsV2` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getblobsv2, or
-// - `engine_getPayloadV5` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getpayloadv5
-// Note: In this function, to stick with the `BlobsBundleV2` format returned by the execution client in `engine_getPayloadV5`,
-// cell proofs are "flattened".
-func ConstructDataColumnSidecars(block interfaces.ReadOnlySignedBeaconBlock, blobs [][]byte, cellProofs [][]byte) ([]*ethpb.DataColumnSidecar, error) {
-	// Check if the cells count is equal to the cell proofs count.
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-	blobCount := uint64(len(blobs))
-	cellProofsCount := uint64(len(cellProofs))
-
-	cellsCount := blobCount * numberOfColumns
-	if cellsCount != cellProofsCount {
-		return nil, ErrBlobsCellsProofsMismatch
-	}
-
-	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
-	for i, blob := range blobs {
-		var kzgBlob kzg.Blob
-		if copy(kzgBlob[:], blob) != len(kzgBlob) {
-			return nil, errors.New("wrong blob size - should never happen")
-		}
-
-		// Compute the extended cells from the (non-extended) blob.
-		cells, err := kzg.ComputeCells(&kzgBlob)
-		if err != nil {
-			return nil, errors.Wrap(err, "compute cells")
-		}
-
-		var proofs []kzg.Proof
-		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
-			var kzgProof kzg.Proof
-			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
-				return nil, errors.New("wrong KZG proof size - should never happen")
-			}
-
-			proofs = append(proofs, kzgProof)
-		}
-
-		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
-		cellsAndProofs = append(cellsAndProofs, cellsProofs)
-	}
-
-	dataColumnSidecars, err := DataColumnSidecars(block, cellsAndProofs)
-	if err != nil {
-		return nil, errors.Wrap(err, "data column sidcars")
-	}
-
-	return dataColumnSidecars, nil
+	return reconstructedVerifiedRoSidecars, nil
 }
 
 // ReconstructBlobs constructs verified read only blobs sidecars from verified read only blob sidecars.
@@ -222,8 +159,8 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 	// Check if the data column sidecars are aligned with the block.
 	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(verifiedDataColumnSidecars))
 	for _, verifiedDataColumnSidecar := range verifiedDataColumnSidecars {
-		dataColumnSicecar := verifiedDataColumnSidecar.RODataColumn
-		dataColumnSidecars = append(dataColumnSidecars, dataColumnSicecar)
+		dataColumnSidecar := verifiedDataColumnSidecar.RODataColumn
+		dataColumnSidecars = append(dataColumnSidecars, dataColumnSidecar)
 	}
 
 	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
@@ -241,7 +178,7 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 		return blobSidecars, nil
 	}
 
-	// We need to reconstruct the blobs.
+	// We need to reconstruct the data column sidecars.
 	reconstructedDataColumnSidecars, err := ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
 	if err != nil {
 		return nil, errors.Wrap(err, "reconstruct data column sidecars")
@@ -256,6 +193,89 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 	return blobSidecars, nil
 }
 
+// ComputeCellsAndProofsFromFlat computes the cells and proofs from blobs and cell flat proofs.
+func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([]kzg.CellsAndProofs, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	blobCount := uint64(len(blobs))
+	cellProofsCount := uint64(len(cellProofs))
+
+	cellsCount := blobCount * numberOfColumns
+	if cellsCount != cellProofsCount {
+		return nil, ErrBlobsCellsProofsMismatch
+	}
+
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
+	for i, blob := range blobs {
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute cells")
+		}
+
+		var proofs []kzg.Proof
+		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
+				return nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			proofs = append(proofs, kzgProof)
+		}
+
+		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
+		cellsAndProofs = append(cellsAndProofs, cellsProofs)
+	}
+
+	return cellsAndProofs, nil
+}
+
+// ComputeCellsAndProofs computes the cells and proofs from blobs and cell proofs.
+func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([]kzg.CellsAndProofs, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, len(blobsAndProofs))
+	for _, blobAndProof := range blobsAndProofs {
+		if blobAndProof == nil {
+			return nil, ErrNilBlobAndProof
+		}
+
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blobAndProof.Blob) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute cells")
+		}
+
+		kzgProofs := make([]kzg.Proof, 0, numberOfColumns*kzg.BytesPerProof)
+		for _, kzgProofBytes := range blobAndProof.KzgProofs {
+			if len(kzgProofBytes) != kzg.BytesPerProof {
+				return nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], kzgProofBytes) != len(kzgProof) {
+				return nil, errors.New("wrong copied KZG proof size - should never happen")
+			}
+
+			kzgProofs = append(kzgProofs, kzgProof)
+		}
+
+		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: kzgProofs}
+		cellsAndProofs = append(cellsAndProofs, cellsProofs)
+	}
+
+	return cellsAndProofs, nil
+}
+
 // blobSidecarsFromDataColumnSidecars converts verified data column sidecars to verified blob sidecars.
 func blobSidecarsFromDataColumnSidecars(roBlock blocks.ROBlock, dataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
 	referenceSidecar := dataColumnSidecars[0]

beacon-chain/core/peerdas/reconstruction_test.go

@@ -9,7 +9,7 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	pb "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/pkg/errors"
@@ -48,7 +48,7 @@ func TestMinimumColumnsCountToReconstruct(t *testing.T) {
 			params.OverrideBeaconConfig(cfg)
 
 			// Compute the minimum number of columns needed to reconstruct.
-			actual := peerdas.MinimumColumnsCountToReconstruct()
+			actual := peerdas.MinimumColumnCountToReconstruct()
 			require.Equal(t, tc.expected, actual)
 		})
 	}
@@ -100,7 +100,7 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 	t.Run("not enough columns to enable reconstruction", func(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
 
-		minimum := peerdas.MinimumColumnsCountToReconstruct()
+		minimum := peerdas.MinimumColumnCountToReconstruct()
 		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars[:minimum-1])
 		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
 	})
@@ -124,50 +124,6 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 	})
 }
 
-func TestConstructDataColumnSidecars(t *testing.T) {
-	const (
-		blobCount    = 3
-		cellsPerBlob = fieldparams.CellsPerBlob
-	)
-
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	// Start the trusted setup.
-	err := kzg.Start()
-	require.NoError(t, err)
-
-	roBlock, _, baseVerifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
-
-	// Extract blobs and proofs from the sidecars.
-	blobs := make([][]byte, 0, blobCount)
-	cellProofs := make([][]byte, 0, cellsPerBlob)
-	for blobIndex := range blobCount {
-		blob := make([]byte, 0, cellsPerBlob)
-		for columnIndex := range cellsPerBlob {
-			cell := baseVerifiedRoSidecars[columnIndex].Column[blobIndex]
-			blob = append(blob, cell...)
-		}
-
-		blobs = append(blobs, blob)
-
-		for columnIndex := range numberOfColumns {
-			cellProof := baseVerifiedRoSidecars[columnIndex].KzgProofs[blobIndex]
-			cellProofs = append(cellProofs, cellProof)
-		}
-	}
-
-	actual, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
-	require.NoError(t, err)
-
-	// Extract the base verified ro sidecars into sidecars.
-	expected := make([]*ethpb.DataColumnSidecar, 0, len(baseVerifiedRoSidecars))
-	for _, verifiedRoSidecar := range baseVerifiedRoSidecars {
-		expected = append(expected, verifiedRoSidecar.DataColumnSidecar)
-	}
-
-	require.DeepSSZEqual(t, expected, actual)
-}
-
 func TestReconstructBlobs(t *testing.T) {
 	// Start the trusted setup.
 	err := kzg.Start()
@@ -196,6 +152,26 @@ func TestReconstructBlobs(t *testing.T) {
 		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
 	})
 
+	t.Run("consecutive duplicates", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// [0, 1, 1, 3, 4, ...]
+		verifiedRoSidecars[2] = verifiedRoSidecars[1]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
+	t.Run("non-consecutive duplicates", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// [0, 1, 2, 1, 4, ...]
+		verifiedRoSidecars[3] = verifiedRoSidecars[1]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
 	t.Run("not enough columns", func(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
 
@@ -230,7 +206,7 @@ func TestReconstructBlobs(t *testing.T) {
 		// Compute cells and proofs from blob sidecars.
 		var wg errgroup.Group
 		blobs := make([][]byte, blobCount)
-		cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		inputCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
 		for i := range blobCount {
 			blob := roBlobSidecars[i].Blob
 			blobs[i] = blob
@@ -247,7 +223,7 @@ func TestReconstructBlobs(t *testing.T) {
 
 				// It is safe for multiple goroutines to concurrently write to the same slice,
 				// as long as they are writing to different indices, which is the case here.
-				cellsAndProofs[i] = cp
+				inputCellsAndProofs[i] = cp
 
 				return nil
 			})
@@ -258,25 +234,24 @@ func TestReconstructBlobs(t *testing.T) {
 
 		// Flatten proofs.
 		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
-		for _, cp := range cellsAndProofs {
+		for _, cp := range inputCellsAndProofs {
 			for _, proof := range cp.Proofs {
 				cellProofs = append(cellProofs, proof[:])
 			}
 		}
 
-		// Construct data column sidecars.
-		// It is OK to use the public function `ConstructDataColumnSidecars`, as long as
-		// `TestConstructDataColumnSidecars` tests pass.
-		dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
+		// Compute celles and proofs from the blobs and cell proofs.
+		cellsAndProofs, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
+		require.NoError(t, err)
+
+		// Construct data column sidears from the signed block and cells and proofs.
+		roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(roBlock))
 		require.NoError(t, err)
 
 		// Convert to verified data column sidecars.
-		verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
-		for _, dataColumnSidecar := range dataColumnSidecars {
-			roSidecar, err := blocks.NewRODataColumn(dataColumnSidecar)
-			require.NoError(t, err)
-
-			verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+		verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))
+		for _, roDataColumnSidecar := range roDataColumnSidecars {
+			verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roDataColumnSidecar)
 			verifiedRoSidecars = append(verifiedRoSidecars, verifiedRoSidecar)
 		}
 
@@ -319,3 +294,162 @@ func TestReconstructBlobs(t *testing.T) {
 	})
 
 }
+
+func TestComputeCellsAndProofsFromFlat(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("mismatched blob and proof counts", func(t *testing.T) {
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+		// Create one blob but proofs for two blobs
+		blobs := [][]byte{{}}
+
+		// Create proofs for 2 blobs worth of columns
+		cellProofs := make([][]byte, 2*numberOfColumns)
+
+		_, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
+		require.ErrorIs(t, err, peerdas.ErrBlobsCellsProofsMismatch)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		const blobCount = 2
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+		// Generate test blobs
+		_, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)
+
+		// Extract blobs and compute expected cells and proofs
+		blobs := make([][]byte, blobCount)
+		expectedCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		var wg errgroup.Group
+
+		for i := range blobCount {
+			blob := roBlobSidecars[i].Blob
+			blobs[i] = blob
+
+			wg.Go(func() error {
+				var kzgBlob kzg.Blob
+				count := copy(kzgBlob[:], blob)
+				require.Equal(t, len(kzgBlob), count)
+
+				cp, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				if err != nil {
+					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
+				}
+
+				expectedCellsAndProofs[i] = cp
+				return nil
+			})
+		}
+
+		err := wg.Wait()
+		require.NoError(t, err)
+
+		// Flatten proofs
+		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
+		for _, cp := range expectedCellsAndProofs {
+			for _, proof := range cp.Proofs {
+				cellProofs = append(cellProofs, proof[:])
+			}
+		}
+
+		// Test ComputeCellsAndProofs
+		actualCellsAndProofs, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
+		require.NoError(t, err)
+		require.Equal(t, blobCount, len(actualCellsAndProofs))
+
+		// Verify the results match expected
+		for i := range blobCount {
+			require.Equal(t, len(expectedCellsAndProofs[i].Cells), len(actualCellsAndProofs[i].Cells))
+			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), len(actualCellsAndProofs[i].Proofs))
+
+			// Compare cells
+			for j, expectedCell := range expectedCellsAndProofs[i].Cells {
+				require.Equal(t, expectedCell, actualCellsAndProofs[i].Cells[j])
+			}
+
+			// Compare proofs
+			for j, expectedProof := range expectedCellsAndProofs[i].Proofs {
+				require.Equal(t, expectedProof, actualCellsAndProofs[i].Proofs[j])
+			}
+		}
+	})
+}
+
+func TestComputeCellsAndProofsFromStructured(t *testing.T) {
+	t.Run("nil blob and proof", func(t *testing.T) {
+		_, err := peerdas.ComputeCellsAndProofsFromStructured([]*pb.BlobAndProofV2{nil})
+		require.ErrorIs(t, err, peerdas.ErrNilBlobAndProof)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		// Start the trusted setup.
+		err := kzg.Start()
+		require.NoError(t, err)
+
+		const blobCount = 2
+
+		// Generate test blobs
+		_, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)
+
+		// Extract blobs and compute expected cells and proofs
+		blobsAndProofs := make([]*pb.BlobAndProofV2, blobCount)
+		expectedCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+
+		var wg errgroup.Group
+		for i := range blobCount {
+			blob := roBlobSidecars[i].Blob
+
+			wg.Go(func() error {
+				var kzgBlob kzg.Blob
+				count := copy(kzgBlob[:], blob)
+				require.Equal(t, len(kzgBlob), count)
+
+				cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				if err != nil {
+					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
+				}
+				expectedCellsAndProofs[i] = cellsAndProofs
+
+				kzgProofs := make([][]byte, 0, len(cellsAndProofs.Proofs))
+				for _, proof := range cellsAndProofs.Proofs {
+					kzgProofs = append(kzgProofs, proof[:])
+				}
+
+				blobAndProof := &pb.BlobAndProofV2{
+					Blob:      blob,
+					KzgProofs: kzgProofs,
+				}
+				blobsAndProofs[i] = blobAndProof
+
+				return nil
+			})
+		}
+
+		err = wg.Wait()
+		require.NoError(t, err)
+
+		// Test ComputeCellsAndProofs
+		actualCellsAndProofs, err := peerdas.ComputeCellsAndProofsFromStructured(blobsAndProofs)
+		require.NoError(t, err)
+		require.Equal(t, blobCount, len(actualCellsAndProofs))
+
+		// Verify the results match expected
+		for i := range blobCount {
+			require.Equal(t, len(expectedCellsAndProofs[i].Cells), len(actualCellsAndProofs[i].Cells))
+			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), len(actualCellsAndProofs[i].Proofs))
+
+			// Compare cells
+			for j, expectedCell := range expectedCellsAndProofs[i].Cells {
+				require.Equal(t, expectedCell, actualCellsAndProofs[i].Cells[j])
+			}
+
+			// Compare proofs
+			for j, expectedProof := range expectedCellsAndProofs[i].Proofs {
+				require.Equal(t, expectedProof, actualCellsAndProofs[i].Proofs[j])
+			}
+		}
+	})
+}

beacon-chain/core/peerdas/validator.go

@@ -1,14 +1,78 @@
 package peerdas
 
 import (
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	beaconState "github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/pkg/errors"
 )
 
+var (
+	ErrNilSignedBlockOrEmptyCellsAndProofs = errors.New("nil signed block or empty cells and proofs")
+	ErrSizeMismatch                        = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
+	ErrNotEnoughDataColumnSidecars         = errors.New("not enough columns")
+	ErrDataColumnSidecarsNotSortedByIndex  = errors.New("data column sidecars are not sorted by index")
+)
+
+var (
+	_ ConstructionPopulator = (*BlockReconstructionSource)(nil)
+	_ ConstructionPopulator = (*SidecarReconstructionSource)(nil)
+)
+
+const (
+	BlockType   = "BeaconBlock"
+	SidecarType = "DataColumnSidecar"
+)
+
+type (
+	// ConstructionPopulator is an interface that can be satisfied by a type that can use data from a struct
+	// like a DataColumnSidecar or a BeaconBlock to set the fields in a data column sidecar that cannot
+	// be obtained from the engine api.
+	ConstructionPopulator interface {
+		Slot() primitives.Slot
+		Root() [fieldparams.RootLength]byte
+		ProposerIndex() primitives.ValidatorIndex
+		Commitments() ([][]byte, error)
+		Type() string
+
+		extract() (*blockInfo, error)
+	}
+
+	// BlockReconstructionSource is a ConstructionPopulator that uses a beacon block as the source of data
+	BlockReconstructionSource struct {
+		blocks.ROBlock
+	}
+
+	// DataColumnSidecar is a ConstructionPopulator that uses a data column sidecar as the source of data
+	SidecarReconstructionSource struct {
+		blocks.VerifiedRODataColumn
+	}
+
+	blockInfo struct {
+		signedBlockHeader *ethpb.SignedBeaconBlockHeader
+		kzgCommitments    [][]byte
+		kzgInclusionProof [][]byte
+	}
+)
+
+// PopulateFromBlock creates a BlockReconstructionSource from a beacon block
+func PopulateFromBlock(block blocks.ROBlock) *BlockReconstructionSource {
+	return &BlockReconstructionSource{ROBlock: block}
+}
+
+// PopulateFromSidecar creates a SidecarReconstructionSource from a data column sidecar
+func PopulateFromSidecar(sidecar blocks.VerifiedRODataColumn) *SidecarReconstructionSource {
+	return &SidecarReconstructionSource{VerifiedRODataColumn: sidecar}
+}
+
 // ValidatorsCustodyRequirement returns the number of custody groups regarding the validator indices attached to the beacon node.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/validator.md#validator-custody
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#validator-custody
 func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validatorsIndex map[primitives.ValidatorIndex]bool) (uint64, error) {
 	totalNodeBalance := uint64(0)
 	for index := range validatorsIndex {
@@ -21,10 +85,165 @@ func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validat
 	}
 
 	beaconConfig := params.BeaconConfig()
-	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
 	validatorCustodyRequirement := beaconConfig.ValidatorCustodyRequirement
 	balancePerAdditionalCustodyGroup := beaconConfig.BalancePerAdditionalCustodyGroup
 
 	count := totalNodeBalance / balancePerAdditionalCustodyGroup
-	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroup), nil
+	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroups), nil
+}
+
+// DataColumnSidecars, given ConstructionPopulator and the cells/proofs associated with each blob in the
+// block, assembles sidecars which can be distributed to peers.
+// This is an adapted version of
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars,
+// which is designed to be used both when constructing sidecars from a block and from a sidecar, replacing
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block and
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_column_sidecar
+func DataColumnSidecars(rows []kzg.CellsAndProofs, src ConstructionPopulator) ([]blocks.RODataColumn, error) {
+	if len(rows) == 0 {
+		return nil, nil
+	}
+	start := time.Now()
+	cells, proofs, err := rotateRowsToCols(rows, params.BeaconConfig().NumberOfColumns)
+	if err != nil {
+		return nil, errors.Wrap(err, "rotate cells and proofs")
+	}
+	info, err := src.extract()
+	if err != nil {
+		return nil, errors.Wrap(err, "extract block info")
+	}
+
+	maxIdx := params.BeaconConfig().NumberOfColumns
+	roSidecars := make([]blocks.RODataColumn, 0, maxIdx)
+	for idx := range maxIdx {
+		sidecar := &ethpb.DataColumnSidecar{
+			Index:                        idx,
+			Column:                       cells[idx],
+			KzgCommitments:               info.kzgCommitments,
+			KzgProofs:                    proofs[idx],
+			SignedBlockHeader:            info.signedBlockHeader,
+			KzgCommitmentsInclusionProof: info.kzgInclusionProof,
+		}
+
+		if len(sidecar.KzgCommitments) != len(sidecar.Column) || len(sidecar.KzgCommitments) != len(sidecar.KzgProofs) {
+			return nil, ErrSizeMismatch
+		}
+
+		roSidecar, err := blocks.NewRODataColumnWithRoot(sidecar, src.Root())
+		if err != nil {
+			return nil, errors.Wrap(err, "new ro data column")
+		}
+		roSidecars = append(roSidecars, roSidecar)
+	}
+
+	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
+	return roSidecars, nil
+}
+
+// Slot returns the slot of the source
+func (s *BlockReconstructionSource) Slot() primitives.Slot {
+	return s.Block().Slot()
+}
+
+// ProposerIndex returns the proposer index of the source
+func (s *BlockReconstructionSource) ProposerIndex() primitives.ValidatorIndex {
+	return s.Block().ProposerIndex()
+}
+
+// Commitments returns the blob KZG commitments of the source
+func (s *BlockReconstructionSource) Commitments() ([][]byte, error) {
+	c, err := s.Block().Body().BlobKzgCommitments()
+
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	return c, nil
+}
+
+// Type returns the type of the source
+func (s *BlockReconstructionSource) Type() string {
+	return BlockType
+}
+
+// extract extracts the block information from the source
+func (b *BlockReconstructionSource) extract() (*blockInfo, error) {
+	block := b.Block()
+
+	header, err := b.Header()
+	if err != nil {
+		return nil, errors.Wrap(err, "header")
+	}
+
+	commitments, err := block.Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "commitments")
+	}
+
+	inclusionProof, err := blocks.MerkleProofKZGCommitments(block.Body())
+	if err != nil {
+		return nil, errors.Wrap(err, "merkle proof kzg commitments")
+	}
+
+	info := &blockInfo{
+		signedBlockHeader: header,
+		kzgCommitments:    commitments,
+		kzgInclusionProof: inclusionProof,
+	}
+
+	return info, nil
+}
+
+// rotateRowsToCols takes a 2D slice of cells and proofs, where the x is rows (blobs) and y is columns,
+// and returns a 2D slice where x is columns and y is rows.
+func rotateRowsToCols(rows []kzg.CellsAndProofs, numCols uint64) ([][][]byte, [][][]byte, error) {
+	if len(rows) == 0 {
+		return nil, nil, nil
+	}
+	cellCols := make([][][]byte, numCols)
+	proofCols := make([][][]byte, numCols)
+	for i, cp := range rows {
+		if uint64(len(cp.Cells)) != numCols {
+			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough cells")
+		}
+		if len(cp.Cells) != len(cp.Proofs) {
+			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough proofs")
+		}
+		for j := uint64(0); j < numCols; j++ {
+			if i == 0 {
+				cellCols[j] = make([][]byte, len(rows))
+				proofCols[j] = make([][]byte, len(rows))
+			}
+			cellCols[j][i] = cp.Cells[j][:]
+			proofCols[j][i] = cp.Proofs[j][:]
+		}
+	}
+	return cellCols, proofCols, nil
+}
+
+// Root returns the block root of the source
+func (s *SidecarReconstructionSource) Root() [fieldparams.RootLength]byte {
+	return s.BlockRoot()
+}
+
+// Commmitments returns the blob KZG commitments of the source
+func (s *SidecarReconstructionSource) Commitments() ([][]byte, error) {
+	return s.KzgCommitments, nil
+}
+
+// Type returns the type of the source
+func (s *SidecarReconstructionSource) Type() string {
+	return SidecarType
+}
+
+// extract extracts the block information from the source
+func (s *SidecarReconstructionSource) extract() (*blockInfo, error) {
+	info := &blockInfo{
+		signedBlockHeader: s.SignedBlockHeader,
+		kzgCommitments:    s.KzgCommitments,
+		kzgInclusionProof: s.KzgCommitmentsInclusionProof,
+	}
+
+	return info, nil
 }

beacon-chain/core/peerdas/validator_test.go

@@ -3,11 +3,15 @@ package peerdas_test
 import (
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
 )
 
 func TestValidatorsCustodyRequirement(t *testing.T) {
@@ -53,3 +57,218 @@ func TestValidatorsCustodyRequirement(t *testing.T) {
 		})
 	}
 }
+
+func TestDataColumnSidecars(t *testing.T) {
+	t.Run("sizes mismatch", func(t *testing.T) {
+		// Create a protobuf signed beacon block.
+		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs.
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, params.BeaconConfig().NumberOfColumns),
+				Proofs: make([]kzg.Proof, params.BeaconConfig().NumberOfColumns),
+			},
+		}
+
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		_, err = peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
+	})
+
+	t.Run("cells array too short for column index", func(t *testing.T) {
+		// Create a Fulu block with a blob commitment.
+		signedBeaconBlockPb := util.NewBeaconBlockFulu()
+		signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{make([]byte, 48)}
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs with insufficient cells for the number of columns.
+		// This simulates a scenario where cellsAndProofs has fewer cells than expected columns.
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, 10),  // Only 10 cells
+				Proofs: make([]kzg.Proof, 10), // Only 10 proofs
+			},
+		}
+
+		// This should fail because the function will try to access columns up to NumberOfColumns
+		// but we only have 10 cells/proofs.
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		_, err = peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("proofs array too short for column index", func(t *testing.T) {
+		// Create a Fulu block with a blob commitment.
+		signedBeaconBlockPb := util.NewBeaconBlockFulu()
+		signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{make([]byte, 48)}
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs with sufficient cells but insufficient proofs.
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, numberOfColumns),
+				Proofs: make([]kzg.Proof, 5), // Only 5 proofs, less than columns
+			},
+		}
+
+		// This should fail when trying to access proof beyond index 4.
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		_, err = peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+		require.ErrorContains(t, "not enough proofs", err)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		// Create a Fulu block with blob commitments.
+		signedBeaconBlockPb := util.NewBeaconBlockFulu()
+		commitment1 := make([]byte, 48)
+		commitment2 := make([]byte, 48)
+
+		// Set different values to distinguish commitments
+		commitment1[0] = 0x01
+		commitment2[0] = 0x02
+		signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{commitment1, commitment2}
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs with correct dimensions.
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, numberOfColumns),
+				Proofs: make([]kzg.Proof, numberOfColumns),
+			},
+			{
+				Cells:  make([]kzg.Cell, numberOfColumns),
+				Proofs: make([]kzg.Proof, numberOfColumns),
+			},
+		}
+
+		// Set distinct values in cells and proofs for testing
+		for i := range numberOfColumns {
+			cellsAndProofs[0].Cells[i][0] = byte(i)
+			cellsAndProofs[0].Proofs[i][0] = byte(i)
+			cellsAndProofs[1].Cells[i][0] = byte(i + 128)
+			cellsAndProofs[1].Proofs[i][0] = byte(i + 128)
+		}
+
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		sidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.NoError(t, err)
+		require.NotNil(t, sidecars)
+		require.Equal(t, int(numberOfColumns), len(sidecars))
+
+		// Verify each sidecar has the expected structure
+		for i, sidecar := range sidecars {
+			require.Equal(t, uint64(i), sidecar.Index)
+			require.Equal(t, 2, len(sidecar.Column))
+			require.Equal(t, 2, len(sidecar.KzgCommitments))
+			require.Equal(t, 2, len(sidecar.KzgProofs))
+
+			// Verify commitments match what we set
+			require.DeepEqual(t, commitment1, sidecar.KzgCommitments[0])
+			require.DeepEqual(t, commitment2, sidecar.KzgCommitments[1])
+
+			// Verify column data comes from the correct cells
+			require.Equal(t, byte(i), sidecar.Column[0][0])
+			require.Equal(t, byte(i+128), sidecar.Column[1][0])
+
+			// Verify proofs come from the correct proofs
+			require.Equal(t, byte(i), sidecar.KzgProofs[0][0])
+			require.Equal(t, byte(i+128), sidecar.KzgProofs[1][0])
+		}
+	})
+}
+
+func TestReconstructionSource(t *testing.T) {
+	// Create a Fulu block with blob commitments.
+	signedBeaconBlockPb := util.NewBeaconBlockFulu()
+	commitment1 := make([]byte, 48)
+	commitment2 := make([]byte, 48)
+
+	// Set different values to distinguish commitments
+	commitment1[0] = 0x01
+	commitment2[0] = 0x02
+	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{commitment1, commitment2}
+
+	// Create a signed beacon block from the protobuf.
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+	require.NoError(t, err)
+
+	// Create cells and proofs with correct dimensions.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	cellsAndProofs := []kzg.CellsAndProofs{
+		{
+			Cells:  make([]kzg.Cell, numberOfColumns),
+			Proofs: make([]kzg.Proof, numberOfColumns),
+		},
+		{
+			Cells:  make([]kzg.Cell, numberOfColumns),
+			Proofs: make([]kzg.Proof, numberOfColumns),
+		},
+	}
+
+	// Set distinct values in cells and proofs for testing
+	for i := range numberOfColumns {
+		cellsAndProofs[0].Cells[i][0] = byte(i)
+		cellsAndProofs[0].Proofs[i][0] = byte(i)
+		cellsAndProofs[1].Cells[i][0] = byte(i + 128)
+		cellsAndProofs[1].Proofs[i][0] = byte(i + 128)
+	}
+
+	rob, err := blocks.NewROBlock(signedBeaconBlock)
+	require.NoError(t, err)
+	sidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+	require.NoError(t, err)
+	require.NotNil(t, sidecars)
+	require.Equal(t, int(numberOfColumns), len(sidecars))
+
+	t.Run("from block", func(t *testing.T) {
+		src := peerdas.PopulateFromBlock(rob)
+		require.Equal(t, rob.Block().Slot(), src.Slot())
+		require.Equal(t, rob.Root(), src.Root())
+		require.Equal(t, rob.Block().ProposerIndex(), src.ProposerIndex())
+
+		commitments, err := src.Commitments()
+		require.NoError(t, err)
+		require.Equal(t, 2, len(commitments))
+		require.DeepEqual(t, commitment1, commitments[0])
+		require.DeepEqual(t, commitment2, commitments[1])
+
+		require.Equal(t, peerdas.BlockType, src.Type())
+	})
+
+	t.Run("from sidecar", func(t *testing.T) {
+		referenceSidecar := blocks.NewVerifiedRODataColumn(sidecars[0])
+		src := peerdas.PopulateFromSidecar(referenceSidecar)
+		require.Equal(t, referenceSidecar.Slot(), src.Slot())
+		require.Equal(t, referenceSidecar.BlockRoot(), src.Root())
+		require.Equal(t, referenceSidecar.ProposerIndex(), src.ProposerIndex())
+
+		commitments, err := src.Commitments()
+		require.NoError(t, err)
+		require.Equal(t, 2, len(commitments))
+		require.DeepEqual(t, commitment1, commitments[0])
+		require.DeepEqual(t, commitment2, commitments[1])
+
+		require.Equal(t, peerdas.SidecarType, src.Type())
+	})
+}

beacon-chain/core/signing/BUILD.bazel

@@ -4,7 +4,6 @@ go_library(
     name = "go_default_library",
     srcs = [
         "domain.go",
-        "signature.go",
         "signing_root.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing",
@@ -25,7 +24,6 @@ go_test(
     name = "go_default_test",
     srcs = [
         "domain_test.go",
-        "signature_test.go",
         "signing_root_test.go",
     ],
     embed = [":go_default_library"],