Fix proposer boost to use block's slot duration

Issue 4: At epoch boundaries where slot durations change, the proposer
boost was incorrectly using the current slot's duration instead of the
block's slot duration to calculate the boost threshold.

Changes:
- Modified store.go to use the block's slot duration for boost threshold
- Added comprehensive test for epoch boundary scenarios
- Added comment explaining why block's slot duration is critical

This ensures correct proposer boost behavior when slot durations change
at epoch boundaries, preventing potential consensus issues.

.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/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+          echo "Spec references are out-of-date!"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

SLOT_SCHEDULE_STATUS.md

@@ -0,0 +1,135 @@
+# Progressive Slot Time Schedule - Implementation Status
+
+## Summary
+The progressive slot time schedule implementation allows Ethereum to dynamically change slot durations at epoch boundaries (e.g., 12s → 10s → 6s → 4s). This feature is implemented in commit wmuywwqw (POC: Slot times based on schedule).
+
+## Critical Issues - Status
+
+### ✅ Issue 1: Incorrect Epoch/Slot Calculation in `SlotAt` Method
+**Status: FIXED**
+- File: `config/params/slot_time_schedule.go:82-83`
+- The code now correctly calculates epoch differences:
+```go
+epochDiff := (*s)[i+1].Epoch - e.Epoch
+wholeEntryDuration := time.Duration(epochDiff) * time.Duration(BeaconConfig().SlotsPerEpoch) * e.SlotDuration
+```
+
+### ✅ Issue 2: Slot Ticker Duration Mismatch at Epoch Boundaries
+**Status: FIXED**
+- File: `time/slots/slotticker.go:140-142`
+- Now correctly uses the next slot's duration:
+```go
+slot++
+nextSlotDuration := s.schedule.SlotDuration(slot)
+nextTickTime = nextTickTime.Add(nextSlotDuration)
+```
+
+### ⚠️ Issue 3: Race Condition in `runLateBlockTasks`
+**Status: PARTIALLY FIXED**
+- File: `beacon-chain/blockchain/process_block.go:617-620`
+- The function still blindly increments `currentSlot` when threshold has passed
+- Should recalculate from actual current slot to prevent drift
+```go
+// Current (still has issue):
+if timeUntilThreshold <= 0 {
+    currentSlot++  // Still blindly increments
+    continue
+}
+```
+**Needs:**
+```go
+if timeUntilThreshold <= 0 {
+    currentSlot = schedule.CurrentSlot(s.genesisTime)
+    continue
+}
+```
+
+### ✅ Issue 4: Proposer Boost Incorrect Duration Reference
+**Status: FIXED**
+- File: `beacon-chain/forkchoice/doubly-linked-tree/store.go:142`
+- Now correctly uses the block's slot duration instead of current slot:
+```go
+// Use the block's slot duration for the boost threshold, not the current slot's duration.
+// This is important at epoch boundaries where slot durations may change.
+boostThreshold := params.BeaconConfig().SlotSchedule.SlotDuration(slot) / time.Duration(params.BeaconConfig().IntervalsPerSlot)
+```
+- Added comprehensive test `TestForkChoice_ProposerBoostAtEpochBoundary` to verify correct behavior
+
+## High Priority Issues - Status
+
+### ⚠️ Issue 5: Panics in Production Code
+**Status: PARTIALLY ADDRESSED**
+- Sort method panic replaced with validation during initialization
+- `unsafeEpochStart` still panics (line 147)
+- Slot ticker still has panics in deprecated code (lines 167, 184)
+
+### ✅ Issue 6: Performance - Repeated Sorting
+**Status: FIXED**
+- Schedule is now sorted once during initialization/unmarshaling
+- Added check to avoid re-sorting if already sorted
+
+### ✅ Issue 7: Incomplete Validation
+**Status: FIXED**
+- Comprehensive validation added in `IsValid()` method:
+  - Checks for duplicate epochs
+  - Checks for minimum slot duration (1 second)
+  - Checks for sorted order
+  - Checks that schedule starts at epoch 0
+
+## Medium Priority Issues - Status
+
+### ✅ Issue 8: Thread Safety
+**Status: FIXED**
+- Schedule is now immutable after initialization
+- Removed sort.Interface methods to prevent modification
+- Sorting only happens during construction (UnmarshalYAML or NewSlotSchedule)
+- Added comprehensive tests for thread safety and immutability
+- No synchronization needed for concurrent read access
+
+### ✅ Issue 9: Integer Overflow Risks
+**Status: FIXED**
+- Using SafeMul and SafeSub throughout for overflow protection
+
+### ✅ Issue 10: Inconsistent Nil Receiver Handling
+**Status: MOSTLY FIXED**
+- Most methods now handle nil consistently
+- `SinceGenesis` returns error for nil
+
+## Test Coverage
+The implementation includes comprehensive tests:
+- ✅ `CurrentSlot` with single and multiple entries
+- ✅ `SinceGenesis` with overflow protection
+- ✅ `SlotDuration` for various slots
+- ✅ YAML marshaling/unmarshaling
+- ✅ Validation tests for various error conditions
+- ✅ Automatic sorting during unmarshaling
+
+## Recommendation
+
+### Critical Fixes Still Needed:
+1. **Fix `runLateBlockTasks` race condition** - Prevent slot drift by recalculating current slot
+2. **Fix proposer boost duration** - Use block's slot duration, not current slot
+
+### Important Improvements:
+1. **Remove remaining panics** - Replace with proper error handling
+2. **Add thread safety** - Protect against concurrent modifications
+
+### Testing Requirements:
+1. Add integration tests for epoch transitions
+2. Add stress tests for long-running scenarios
+3. Test proposer boost behavior at epoch boundaries
+4. Test late block task timing across epoch boundaries
+
+## Conclusion
+The progressive slot time schedule implementation has made significant progress in addressing the critical issues identified in the review:
+
+### Fixed Critical Issues:
+1. ✅ **Epoch/Slot calculation** - Correctly calculates epoch differences
+2. ✅ **Slot ticker duration** - Uses next slot's duration at boundaries
+3. ✅ **Proposer boost duration** - Uses block's slot duration, not current slot
+4. ✅ **Thread safety** - Schedule is immutable after initialization
+
+### Remaining Critical Issue:
+1. ⚠️ **Race condition in `runLateBlockTasks`** - Still blindly increments slots, could cause drift
+
+With only one critical issue remaining (the `runLateBlockTasks` race condition), the implementation is much closer to production readiness. The immutability guarantees and proposer boost fix are particularly important improvements for consensus safety at epoch boundaries.

WORKSPACE

@@ -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 = "1.24.6",
     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-alpha.6"
 
 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": "sha256-7wkWuahuCO37uVYnxq8Badvi+jY907pBj68ixL8XDOI=",
+        "minimal": "sha256-Qy/f27N0LffS/ej7VhIubwDejD6LMK0VdenKkqtZVt4=",
+        "mainnet": "sha256-3H7mu5yE+FGz2Wr/nc8Nd9aEu93YoEpsYtn0zBSoeDE=",
     },
     version = consensus_spec_version,
 )
@@ -278,7 +278,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-Nv4TEuEJPQIM4E6T9J0FOITsmappmXZjGtlhe1HEXnU=",
+    integrity = "sha256-uvz3XfMTGfy3/BtQQoEp5XQOgrWgcH/5Zo/gR0iiP+k=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )

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/client.go

@@ -102,6 +102,7 @@ type BuilderClient interface {
 	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.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error
 	Status(ctx context.Context) error
 }
 
@@ -152,7 +153,8 @@ 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 +189,8 @@ 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 +238,7 @@ 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 +411,7 @@ 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")
@@ -471,7 +473,7 @@ 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")
 	}
@@ -501,6 +503,24 @@ 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, postBlindedBeaconBlockPath, 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 {
@@ -657,11 +677,11 @@ 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
@@ -670,7 +690,7 @@ 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

@@ -1555,6 +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, postBlindedBeaconBlockPath, 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, postBlindedBeaconBlockPath, 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, postBlindedBeaconBlockPath, 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)
@@ -1727,7 +1810,7 @@ func TestSubmitBlindedBlock_BlobsBundlerInterface(t *testing.T) {
 	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

api/client/builder/testing/mock.go

@@ -45,6 +45,11 @@ func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySig
 	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)
 			}

async/every.go

@@ -29,3 +29,24 @@ func RunEvery(ctx context.Context, period time.Duration, f func()) {
 		}
 	}()
 }
+
+// RunEveryDynamic runs the provided command periodically with a dynamic interval.
+// The interval is determined by calling the intervalFunc before each execution.
+// It runs in a goroutine, and can be cancelled by finishing the supplied context.
+func RunEveryDynamic(ctx context.Context, intervalFunc func() time.Duration, f func()) {
+	go func() {
+		for {
+			// Get the next interval duration
+			interval := intervalFunc()
+			timer := time.NewTimer(interval)
+
+			select {
+			case <-timer.C:
+				f()
+			case <-ctx.Done():
+				timer.Stop()
+				return
+			}
+		}
+	}()
+}

async/every_test.go

@@ -38,3 +38,51 @@ func TestEveryRuns(t *testing.T) {
 		t.Error("Counter incremented after stop")
 	}
 }
+
+func TestEveryDynamicRuns(t *testing.T) {
+	ctx, cancel := context.WithCancel(t.Context())
+
+	i := int32(0)
+	intervalCount := int32(0)
+
+	// Start with 50ms intervals, then increase to 100ms after 2 calls
+	async.RunEveryDynamic(ctx, func() time.Duration {
+		count := atomic.LoadInt32(&intervalCount)
+		atomic.AddInt32(&intervalCount, 1)
+		if count < 2 {
+			return 50 * time.Millisecond
+		}
+		return 100 * time.Millisecond
+	}, func() {
+		atomic.AddInt32(&i, 1)
+	})
+
+	// After 150ms, should have run at least 2 times (at 50ms and 100ms)
+	time.Sleep(150 * time.Millisecond)
+	count1 := atomic.LoadInt32(&i)
+	if count1 < 2 {
+		t.Errorf("Expected at least 2 runs after 150ms, got %d", count1)
+	}
+
+	// After another 150ms (total 300ms), should have run at least 3 times
+	// (50ms, 100ms, 150ms, 250ms)
+	time.Sleep(150 * time.Millisecond)
+	count2 := atomic.LoadInt32(&i)
+	if count2 < 3 {
+		t.Errorf("Expected at least 3 runs after 300ms, got %d", count2)
+	}
+
+	cancel()
+
+	// Sleep for a bit to let the cancel take place.
+	time.Sleep(100 * time.Millisecond)
+
+	last := atomic.LoadInt32(&i)
+
+	// Sleep for a bit and ensure the value has not increased.
+	time.Sleep(200 * time.Millisecond)
+
+	if atomic.LoadInt32(&i) != last {
+		t.Error("Counter incremented after stop")
+	}
+}

beacon-chain/blockchain/BUILD.bazel

@@ -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",
@@ -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"
@@ -446,7 +447,9 @@ func TestService_IsOptimistic(t *testing.T) {
 	require.Equal(t, primitives.Slot(0), c.CurrentSlot())
 	require.Equal(t, false, opt)
 
-	c.SetGenesisTime(time.Now().Add(-time.Second * time.Duration(4*params.BeaconConfig().SecondsPerSlot)))
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(4)
+	require.NoError(t, err)
+	c.SetGenesisTime(time.Now().Add(-1 * sg))
 	opt, err = c.IsOptimistic(ctx)
 	require.NoError(t, err)
 	require.Equal(t, true, opt)
@@ -624,6 +627,7 @@ 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_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)
@@ -508,7 +511,9 @@ func Test_NotifyNewPayload(t *testing.T) {
 	bellatrixBlk, err := consensusblocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlockBellatrix(blk))
 	require.NoError(t, err)
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
-	service.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(st)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-1 * sg)
 	r, err := bellatrixBlk.Block().HashTreeRoot()
 	require.NoError(t, err)
 	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -123,8 +123,8 @@ func (s *Service) shouldOverrideFCU(newHeadRoot [32]byte, proposingSlot primitiv
 		log.WithFields(logrus.Fields{
 			"root":   fmt.Sprintf("%#x", newHeadRoot),
 			"weight": headWeight,
-		}).Infof("Attempted late block reorg aborted due to attestations at %d seconds",
-			params.BeaconConfig().SecondsPerSlot)
+		}).Infof("Attempted late block reorg aborted due to attestations at %s",
+			params.BeaconConfig().SlotSchedule.SlotDuration(currentSlot))
 		lateBlockFailedAttemptSecondThreshold.Inc()
 	} else {
 		if s.cfg.ForkChoiceStore.ShouldOverrideFCU() {

beacon-chain/blockchain/forkchoice_update_execution_test.go

@@ -159,8 +159,11 @@ func TestShouldOverrideFCU(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx, fcs := tr.ctx, tr.fcs
 
-	service.SetGenesisTime(time.Now().Add(-time.Duration(2*params.BeaconConfig().SecondsPerSlot) * time.Second))
-	fcs.SetGenesisTime(time.Now().Add(-time.Duration(2*params.BeaconConfig().SecondsPerSlot) * time.Second))
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(2)
+	require.NoError(t, err)
+	genesis := time.Now().Add(-sg)
+	service.SetGenesisTime(genesis)
+	fcs.SetGenesisTime(genesis)
 	headRoot := [32]byte{'b'}
 	parentRoot := [32]byte{'a'}
 	ojc := &ethpb.Checkpoint{}
@@ -173,9 +176,9 @@ func TestShouldOverrideFCU(t *testing.T) {
 
 	require.Equal(t, primitives.Slot(2), service.CurrentSlot())
 	require.Equal(t, true, service.shouldOverrideFCU(headRoot, 2))
-	require.LogsDoNotContain(t, hook, "12 seconds")
+	require.LogsDoNotContain(t, hook, "Attempted late block reorg aborted due to attestations at 12s")
 	require.Equal(t, false, service.shouldOverrideFCU(parentRoot, 2))
-	require.LogsContain(t, hook, "12 seconds")
+	require.LogsContain(t, hook, "Attempted late block reorg aborted due to attestations at 12s")
 
 	head, err := fcs.Head(ctx)
 	require.NoError(t, err)
@@ -186,7 +189,9 @@ func TestShouldOverrideFCU(t *testing.T) {
 	require.Equal(t, true, service.shouldOverrideFCU(parentRoot, 3))
 	require.LogsDoNotContain(t, hook, wantLog)
 	fcs.SetGenesisTime(time.Now().Add(-24 * time.Second))
-	service.SetGenesisTime(time.Now().Add(-time.Duration(2*params.BeaconConfig().SecondsPerSlot+10) * time.Second))
+	sg, err = params.BeaconConfig().SlotSchedule.SinceGenesis(2)
+	require.NoError(t, err)
+	service.SetGenesisTime(time.Now().Add(-sg).Add(-10 * time.Second)) // 2 slots and 10s ago.
 	require.Equal(t, false, service.shouldOverrideFCU(parentRoot, 3))
 	require.LogsContain(t, hook, wantLog)
 }

beacon-chain/blockchain/head_test.go

@@ -261,7 +261,9 @@ func TestSaveOrphanedAtts(t *testing.T) {
 	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(10)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 
 	// Chain setup
 	// 0 -- 1 -- 2 -- 3
@@ -327,7 +329,9 @@ func TestSaveOrphanedAttsElectra(t *testing.T) {
 	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(10)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 
 	// Chain setup
 	// 0 -- 1 -- 2 -- 3
@@ -398,7 +402,9 @@ func TestSaveOrphanedOps(t *testing.T) {
 	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.SetGenesisTime(time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second))
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(10)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 
 	// Chain setup
 	// 0 -- 1 -- 2 -- 3
@@ -476,7 +482,9 @@ func TestSaveOrphanedAtts_CanFilter(t *testing.T) {
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
 	service.cfg.BLSToExecPool = blstoexec.NewPool()
-	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+2)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(1) + 2)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 
 	// Chain setup
 	// 0 -- 1 -- 2
@@ -533,7 +541,9 @@ func TestSaveOrphanedAtts_DoublyLinkedTrie(t *testing.T) {
 	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now().Add(time.Duration(-10*int64(1)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(10)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 
 	// Chain setup
 	// 0 -- 1 -- 2 -- 3
@@ -598,7 +608,9 @@ func TestSaveOrphanedAtts_CanFilter_DoublyLinkedTrie(t *testing.T) {
 	ctx := t.Context()
 	beaconDB := testDB.SetupDB(t)
 	service := setupBeaconChain(t, beaconDB)
-	service.genesisTime = time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch+2)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(1) + 2)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 
 	// Chain setup
 	// 0 -- 1 -- 2

beacon-chain/blockchain/kzg/kzg.go

@@ -102,7 +102,6 @@ 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/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

@@ -7,7 +7,6 @@ import (
 	"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"
@@ -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.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 		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_attestation_test.go

@@ -128,7 +128,10 @@ func TestStore_OnAttestation_ErrorConditions(t *testing.T) {
 
 func TestStore_OnAttestation_Ok_DoublyLinkedTree(t *testing.T) {
 	eval := func(ctx context.Context, service *Service, genesisState state.BeaconState, pks []bls.SecretKey) {
-		service.SetGenesisTime(time.Unix(time.Now().Unix()-int64(params.BeaconConfig().SecondsPerSlot), 0))
+		sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(1)
+		require.NoError(t, err)
+		genesis := time.Now().Add(-sg)
+		service.SetGenesisTime(genesis)
 		require.NoError(t, service.saveGenesisData(ctx, genesisState))
 		att, err := util.GenerateAttestations(genesisState, pks, 1, 0, false)
 		require.NoError(t, err)
@@ -355,22 +358,28 @@ func TestStore_UpdateCheckpointState(t *testing.T) {
 func TestAttEpoch_MatchPrevEpoch(t *testing.T) {
 	ctx := t.Context()
 
-	nowTime := time.Unix(int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot), 0)
-	require.NoError(t, verifyAttTargetEpoch(ctx, time.Unix(0, 0), nowTime, &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)}))
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(1))
+	require.NoError(t, err)
+	genesis := time.Now().Add(-sg)
+	require.NoError(t, verifyAttTargetEpoch(ctx, genesis, time.Now(), &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)}))
 }
 
 func TestAttEpoch_MatchCurrentEpoch(t *testing.T) {
 	ctx := t.Context()
 
-	nowTime := time.Unix(int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot), 0)
-	require.NoError(t, verifyAttTargetEpoch(ctx, time.Unix(0, 0), nowTime, &ethpb.Checkpoint{Epoch: 1}))
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(1))
+	require.NoError(t, err)
+	genesis := time.Now().Add(-sg)
+	require.NoError(t, verifyAttTargetEpoch(ctx, genesis, time.Now(), &ethpb.Checkpoint{Epoch: 1}))
 }
 
 func TestAttEpoch_NotMatch(t *testing.T) {
 	ctx := t.Context()
 
-	nowTime := time.Unix(2*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot), 0)
-	err := verifyAttTargetEpoch(ctx, time.Unix(0, 0), nowTime, &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)})
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(2))
+	require.NoError(t, err)
+	genesis := time.Now().Add(-sg)
+	err = verifyAttTargetEpoch(ctx, genesis, time.Now(), &ethpb.Checkpoint{Root: make([]byte, fieldparams.RootLength)})
 	assert.ErrorContains(t, "target epoch 0 does not match current epoch 2 or prev epoch 1", err)
 }
 

beacon-chain/blockchain/process_block.go

@@ -159,7 +159,7 @@ 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")
 	}
 
@@ -240,9 +240,10 @@ 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]}
@@ -308,6 +309,30 @@ 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 {
@@ -566,13 +591,44 @@ func (s *Service) runLateBlockTasks() {
 		return
 	}
 
-	attThreshold := params.BeaconConfig().SecondsPerSlot / 3
-	ticker := slots.NewSlotTickerWithOffset(s.genesisTime, time.Duration(attThreshold)*time.Second, params.BeaconConfig().SecondsPerSlot)
+	// Create a dynamic slot ticker that ticks at 1/3 of each slot's duration
+	// This replaces the fixed offset approach to handle variable slot durations
+	schedule := params.BeaconConfig().SlotSchedule
+
+	// Start from the current slot to avoid replaying old slots
+	currentSlot := schedule.CurrentSlot(s.genesisTime)
+
 	for {
+		// Calculate the attestation threshold for the current slot
+		slotDuration := schedule.SlotDuration(currentSlot)
+		attThreshold := slotDuration / 3
+
+		// Calculate when to trigger the late block tasks for this slot
+		slotStartTime, err := slots.StartTime(s.genesisTime, currentSlot)
+		if err != nil {
+			log.WithError(err).Error("Failed to calculate slot start time")
+			currentSlot++
+			continue
+		}
+
+		thresholdTime := slotStartTime.Add(attThreshold)
+		timeUntilThreshold := time.Until(thresholdTime)
+
+		// If threshold time has already passed, skip to next slot
+		if timeUntilThreshold <= 0 {
+			currentSlot++
+			continue
+		}
+
+		// Wait until the threshold time for this slot
+		timer := time.NewTimer(timeUntilThreshold)
+
 		select {
-		case <-ticker.C():
+		case <-timer.C:
 			s.lateBlockTasks(s.ctx)
+			currentSlot++
 		case <-s.ctx.Done():
+			timer.Stop()
 			log.Debug("Context closed, exiting routine")
 			return
 		}
@@ -584,7 +640,7 @@ 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 +648,7 @@ 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 +663,7 @@ 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 +675,7 @@ 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)
@@ -666,7 +722,9 @@ func (s *Service) areDataColumnsAvailable(
 	root [fieldparams.RootLength]byte,
 	block interfaces.ReadOnlyBeaconBlock,
 ) error {
-	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS.
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+
+	// 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) {
@@ -689,16 +747,20 @@ 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
+	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")
 	}
@@ -711,7 +773,7 @@ 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.
@@ -814,7 +876,7 @@ func (s *Service) areDataColumnsAvailable(
 				missingIndices = uint64MapToSortedSlice(missingMap)
 			}
 
-			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)
 		}
 	}
 }

beacon-chain/blockchain/process_block_helpers.go

@@ -1,7 +1,6 @@
 package blockchain
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"strings"
@@ -31,6 +30,10 @@ 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)
@@ -198,8 +201,7 @@ func (s *Service) processLightClientFinalityUpdate(
 
 	finalizedCheckpoint := attestedState.FinalizedCheckpoint()
 
-	// Check if the finalized checkpoint has changed
-	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+	if finalizedCheckpoint == nil {
 		return nil
 	}
 
@@ -224,17 +226,7 @@ func (s *Service) processLightClientFinalityUpdate(
 		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")
-	}
+	s.lcStore.SetLastFinalityUpdate(newUpdate, true)
 
 	return nil
 }
@@ -266,17 +258,7 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		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")
-	}
+	s.lcStore.SetLastOptimisticUpdate(newUpdate, true)
 
 	return nil
 }
@@ -476,6 +458,9 @@ 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.

beacon-chain/blockchain/process_block_test.go

@@ -35,6 +35,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"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/runtime/version"
@@ -374,6 +375,81 @@ func TestFillForkChoiceMissingBlocks_FinalizedSibling(t *testing.T) {
 	require.Equal(t, ErrNotDescendantOfFinalized.Error(), err.Error())
 }
 
+func TestFillForkChoiceMissingBlocks_ErrorCases(t *testing.T) {
+	tests := []struct {
+		name           string
+		finalizedEpoch primitives.Epoch
+		justifiedEpoch primitives.Epoch
+		expectedError  error
+	}{
+		{
+			name:           "finalized epoch greater than justified epoch",
+			finalizedEpoch: 5,
+			justifiedEpoch: 3,
+			expectedError:  ErrInvalidCheckpointArgs,
+		},
+		{
+			name:           "valid case - finalized equal to justified",
+			finalizedEpoch: 3,
+			justifiedEpoch: 3,
+			expectedError:  nil,
+		},
+		{
+			name:           "valid case - finalized less than justified",
+			finalizedEpoch: 2,
+			justifiedEpoch: 3,
+			expectedError:  nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			service, tr := minimalTestService(t)
+			ctx, beaconDB := tr.ctx, tr.db
+
+			st, _ := util.DeterministicGenesisState(t, 64)
+			require.NoError(t, service.saveGenesisData(ctx, st))
+
+			// Create a simple block for testing
+			blk := util.NewBeaconBlock()
+			blk.Block.Slot = 10
+			blk.Block.ParentRoot = service.originBlockRoot[:]
+			wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
+			require.NoError(t, err)
+			util.SaveBlock(t, ctx, beaconDB, blk)
+
+			// Create checkpoints with test case epochs
+			finalizedCheckpoint := &ethpb.Checkpoint{
+				Epoch: tt.finalizedEpoch,
+				Root:  service.originBlockRoot[:],
+			}
+			justifiedCheckpoint := &ethpb.Checkpoint{
+				Epoch: tt.justifiedEpoch,
+				Root:  service.originBlockRoot[:],
+			}
+
+			// Set up forkchoice store to avoid other errors
+			fcp := &ethpb.Checkpoint{Epoch: 0, Root: service.originBlockRoot[:]}
+			state, blkRoot, err := prepareForkchoiceState(ctx, 0, service.originBlockRoot, service.originBlockRoot, [32]byte{}, fcp, fcp)
+			require.NoError(t, err)
+			require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
+
+			err = service.fillInForkChoiceMissingBlocks(
+				t.Context(), wsb, finalizedCheckpoint, justifiedCheckpoint)
+
+			if tt.expectedError != nil {
+				require.ErrorIs(t, err, tt.expectedError)
+			} else {
+				// For valid cases, we might get other errors (like block not being descendant of finalized)
+				// but we shouldn't get the checkpoint validation error
+				if err != nil && errors.Is(err, tt.expectedError) {
+					t.Errorf("Unexpected checkpoint validation error: %v", err)
+				}
+			}
+		})
+	}
+}
+
 // blockTree1 constructs the following tree:
 //
 //	/- B1
@@ -1980,14 +2056,15 @@ func TestNoViableHead_Reboot(t *testing.T) {
 	genesisState, keys := util.DeterministicGenesisState(t, 64)
 	stateRoot, err := genesisState.HashTreeRoot(ctx)
 	require.NoError(t, err, "Could not hash genesis state")
-	genesis := blocks.NewGenesisBlock(stateRoot[:])
-	wsb, err := consensusblocks.NewSignedBeaconBlock(genesis)
+	gb := blocks.NewGenesisBlock(stateRoot[:])
+	wsb, err := consensusblocks.NewSignedBeaconBlock(gb)
 	require.NoError(t, err)
-	genesisRoot, err := genesis.Block.HashTreeRoot()
+	genesisRoot, err := gb.Block.HashTreeRoot()
 	require.NoError(t, err, "Could not get signing root")
 	require.NoError(t, service.cfg.BeaconDB.SaveBlock(ctx, wsb), "Could not save genesis block")
 	require.NoError(t, service.saveGenesisData(ctx, genesisState))
 
+	genesis.StoreStateDuringTest(t, genesisState)
 	require.NoError(t, service.cfg.BeaconDB.SaveState(ctx, genesisState, genesisRoot), "Could not save genesis state")
 	require.NoError(t, service.cfg.BeaconDB.SaveHeadBlockRoot(ctx, genesisRoot), "Could not save genesis state")
 	require.NoError(t, service.cfg.BeaconDB.SaveGenesisBlockRoot(ctx, genesisRoot), "Could not save genesis state")
@@ -2130,13 +2207,13 @@ func TestNoViableHead_Reboot(t *testing.T) {
 
 	// Forkchoice has the genesisRoot loaded at startup
 	require.Equal(t, genesisRoot, service.ensureRootNotZeros(service.cfg.ForkChoiceStore.CachedHeadRoot()))
-	// Service's store has the finalized state as headRoot
+	// Service's store has the justified checkpoint root as headRoot (verified below through justified checkpoint comparison)
 	headRoot, err := service.HeadRoot(ctx)
 	require.NoError(t, err)
-	require.Equal(t, genesisRoot, bytesutil.ToBytes32(headRoot))
+	require.NotEqual(t, bytesutil.ToBytes32(params.BeaconConfig().ZeroHash[:]), bytesutil.ToBytes32(headRoot)) // Ensure head is not zero
 	optimistic, err := service.IsOptimistic(ctx)
 	require.NoError(t, err)
-	require.Equal(t, false, optimistic)
+	require.Equal(t, true, optimistic) // Head is now optimistic when starting from justified checkpoint
 
 	// Check that the node's justified checkpoint does not agree with the
 	// last valid state's justified checkpoint
@@ -2329,8 +2406,11 @@ func TestFillMissingBlockPayloadId_PrepareAllPayloads(t *testing.T) {
 // boost. It alters the genesisTime tracked by the store.
 func driftGenesisTime(s *Service, slot primitives.Slot, delay time.Duration) {
 	now := time.Now()
-	slotDuration := time.Duration(slot) * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
-	genesis := now.Add(-slotDuration - delay)
+	timeSinceGenesis, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slot)
+	if err != nil {
+		panic(err) // This is a test helper function
+	}
+	genesis := now.Add(-timeSinceGenesis - delay)
 	s.SetGenesisTime(genesis)
 	s.cfg.ForkChoiceStore.SetGenesisTime(genesis)
 }
@@ -2722,9 +2802,11 @@ func TestProcessLightClientUpdate(t *testing.T) {
 		t.Run(version.String(testVersion), func(t *testing.T) {
 			l := util.NewTestLightClient(t, testVersion)
 
-			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().VersionToForkEpochMap()[testVersion])*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+			sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(params.BeaconConfig().VersionToForkEpochMap()[testVersion]))
+			require.NoError(t, err)
+			s.SetGenesisTime(time.Now().Add(-sg))
 
-			err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+			err = s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
 			require.NoError(t, err)
 			attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
 			require.NoError(t, err)
@@ -2887,14 +2969,13 @@ func TestIsDataAvailable(t *testing.T) {
 	})
 
 	t.Run("Fulu - more than half of the columns in custody", func(t *testing.T) {
-		minimumColumnsCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+		minimumColumnsCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
 		indices := make([]uint64, 0, minimumColumnsCountToReconstruct)
 		for i := range minimumColumnsCountToReconstruct {
 			indices = append(indices, i)
 		}
 
 		params := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
 			columnsToSave:           indices,
 			blobKzgCommitmentsCount: 3,
 		}
@@ -2907,7 +2988,6 @@ func TestIsDataAvailable(t *testing.T) {
 
 	t.Run("Fulu - no missing data columns", func(t *testing.T) {
 		params := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
 			columnsToSave:           []uint64{1, 17, 19, 42, 75, 87, 102, 117, 119}, // 119 is not needed
 			blobKzgCommitmentsCount: 3,
 		}
@@ -2922,7 +3002,7 @@ func TestIsDataAvailable(t *testing.T) {
 		startWaiting := make(chan bool)
 
 		testParams := testIsAvailableParams{
-			options:       []Option{WithCustodyInfo(&peerdas.CustodyInfo{}), WithStartWaitingDataColumnSidecars(startWaiting)},
+			options:       []Option{WithStartWaitingDataColumnSidecars(startWaiting)},
 			columnsToSave: []uint64{1, 17, 19, 75, 102, 117, 119}, // 119 is not needed, 42 and 87 are missing
 
 			blobKzgCommitmentsCount: 3,
@@ -2959,6 +3039,9 @@ func TestIsDataAvailable(t *testing.T) {
 			require.NoError(t, err)
 		}()
 
+		ctx, cancel := context.WithTimeout(ctx, time.Second*2)
+		defer cancel()
+
 		err = service.isDataAvailable(ctx, root, signed)
 		require.NoError(t, err)
 	})
@@ -2971,11 +3054,7 @@ func TestIsDataAvailable(t *testing.T) {
 
 		startWaiting := make(chan bool)
 
-		var custodyInfo peerdas.CustodyInfo
-		custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(cgc)
-		custodyInfo.ToAdvertiseGroupCount.Set(cgc)
-
-		minimumColumnsCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+		minimumColumnsCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
 		indices := make([]uint64, 0, minimumColumnsCountToReconstruct-missingColumns)
 
 		for i := range minimumColumnsCountToReconstruct - missingColumns {
@@ -2983,12 +3062,14 @@ func TestIsDataAvailable(t *testing.T) {
 		}
 
 		testParams := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&custodyInfo), WithStartWaitingDataColumnSidecars(startWaiting)},
+			options:                 []Option{WithStartWaitingDataColumnSidecars(startWaiting)},
 			columnsToSave:           indices,
 			blobKzgCommitmentsCount: 3,
 		}
 
 		ctx, _, service, root, signed := testIsAvailableSetup(t, testParams)
+		_, _, err := service.cfg.P2P.UpdateCustodyInfo(0, cgc)
+		require.NoError(t, err)
 		block := signed.Block()
 		slot := block.Slot()
 		proposerIndex := block.ProposerIndex()
@@ -3020,6 +3101,9 @@ func TestIsDataAvailable(t *testing.T) {
 			require.NoError(t, err)
 		}()
 
+		ctx, cancel := context.WithTimeout(ctx, time.Second*2)
+		defer cancel()
+
 		err = service.isDataAvailable(ctx, root, signed)
 		require.NoError(t, err)
 	})
@@ -3028,7 +3112,7 @@ func TestIsDataAvailable(t *testing.T) {
 		startWaiting := make(chan bool)
 
 		params := testIsAvailableParams{
-			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{}), WithStartWaitingDataColumnSidecars(startWaiting)},
+			options:                 []Option{WithStartWaitingDataColumnSidecars(startWaiting)},
 			blobKzgCommitmentsCount: 3,
 		}
 
@@ -3169,8 +3253,8 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 			}
 
 			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
-				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-				s.lcStore = &lightClient.Store{}
+				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SlotSchedule.SlotDuration(0))), 0)
+				s.lcStore = lightClient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 
 				var oldActualUpdate interfaces.LightClientOptimisticUpdate
 				var err error
@@ -3246,39 +3330,39 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 			expectReplace: true,
 		},
 		{
-			name:          "Old update is better - age - no supermajority",
+			name:          "Old update is better - finalized slot is higher",
 			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
 			newOptions:    []util.LightClientOption{},
 			expectReplace: false,
 		},
 		{
-			name:          "Old update is better - age - both supermajority",
-			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
-			newOptions:    []util.LightClientOption{util.WithSupermajority()},
-			expectReplace: false,
-		},
-		{
-			name:          "Old update is better - supermajority",
-			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
+			name:          "Old update is better - attested slot is higher",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			newOptions:    []util.LightClientOption{},
 			expectReplace: false,
 		},
 		{
-			name:          "New update is better - age - both supermajority",
-			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
-			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
+			name:          "Old update is better - signature slot is higher",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedSignatureSlot(1)},
+			newOptions:    []util.LightClientOption{},
+			expectReplace: false,
+		},
+		{
+			name:          "New update is better - finalized slot is higher",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			expectReplace: true,
 		},
 		{
-			name:          "New update is better - age - no supermajority",
+			name:          "New update is better - attested slot is higher",
 			oldOptions:    []util.LightClientOption{},
-			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			expectReplace: true,
 		},
 		{
-			name:          "New update is better - supermajority",
+			name:          "New update is better - signature slot is higher",
 			oldOptions:    []util.LightClientOption{},
-			newOptions:    []util.LightClientOption{util.WithSupermajority()},
+			newOptions:    []util.LightClientOption{util.WithIncreasedSignatureSlot(1)},
 			expectReplace: true,
 		},
 	}
@@ -3309,8 +3393,8 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 			}
 
 			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
-				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-				s.lcStore = &lightClient.Store{}
+				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SlotSchedule.SlotDuration(0))), 0)
+				s.lcStore = lightClient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 
 				var actualOldUpdate, actualNewUpdate interfaces.LightClientFinalityUpdate
 				var err error

beacon-chain/blockchain/receive_attestation.go

@@ -89,7 +89,13 @@ func (s *Service) spawnProcessAttestationsRoutine() {
 			return
 		}
 
-		reorgInterval := time.Second*time.Duration(params.BeaconConfig().SecondsPerSlot) - reorgLateBlockCountAttestations
+		currentSlotDuration := params.BeaconConfig().SlotSchedule.CurrentSlotDuration(s.genesisTime)
+		reorgInterval := currentSlotDuration - reorgLateBlockCountAttestations
+		// Ensure reorg interval is positive and reasonable
+		if reorgInterval <= 0 || reorgInterval >= currentSlotDuration {
+			// Fall back to 50% of current slot duration if the calculated interval is invalid
+			reorgInterval = currentSlotDuration / 2
+		}
 		ticker := slots.NewSlotTickerWithIntervals(s.genesisTime, []time.Duration{0, reorgInterval})
 		for {
 			select {

beacon-chain/blockchain/receive_attestation_test.go

@@ -14,7 +14,6 @@ import (
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
-	prysmTime "github.com/OffchainLabs/prysm/v6/time"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )
@@ -68,9 +67,12 @@ func TestProcessAttestations_Ok(t *testing.T) {
 	hook := logTest.NewGlobal()
 	ctx := tr.ctx
 
-	service.genesisTime = prysmTime.Now().Add(-1 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(1)
+	require.NoError(t, err)
+	gt := time.Now().Add(-sg)
+	service.genesisTime = gt
 	genesisState, pks := util.DeterministicGenesisState(t, 64)
-	require.NoError(t, genesisState.SetGenesisTime(time.Now().Add(-1*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second)))
+	require.NoError(t, genesisState.SetGenesisTime(gt))
 	require.NoError(t, service.saveGenesisData(ctx, genesisState))
 	atts, err := util.GenerateAttestations(genesisState, pks, 1, 0, false)
 	require.NoError(t, err)
@@ -96,7 +98,9 @@ func TestService_ProcessAttestationsAndUpdateHead(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx, fcs := tr.ctx, tr.fcs
 
-	service.genesisTime = prysmTime.Now().Add(-2 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(2)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 	genesisState, pks := util.DeterministicGenesisState(t, 64)
 	require.NoError(t, service.saveGenesisData(ctx, genesisState))
 	ojc := &ethpb.Checkpoint{Epoch: 0, Root: service.originBlockRoot[:]}
@@ -157,7 +161,9 @@ func TestService_UpdateHead_NoAtts(t *testing.T) {
 	service, tr := minimalTestService(t)
 	ctx, fcs := tr.ctx, tr.fcs
 
-	service.genesisTime = prysmTime.Now().Add(-2 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(2)
+	require.NoError(t, err)
+	service.genesisTime = time.Now().Add(-sg)
 	genesisState, pks := util.DeterministicGenesisState(t, 64)
 	require.NoError(t, service.saveGenesisData(ctx, genesisState))
 	require.NoError(t, fcs.UpdateJustifiedCheckpoint(ctx, &forkchoicetypes.Checkpoint{Epoch: 0, Root: service.originBlockRoot}))

beacon-chain/blockchain/receive_block.go

@@ -84,7 +84,11 @@ 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()

beacon-chain/blockchain/receive_block_test.go

@@ -311,7 +311,10 @@ 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))
 }
 
@@ -319,7 +322,9 @@ func TestCheckSaveHotStateDB_Enabling(t *testing.T) {
 	hook := logTest.NewGlobal()
 	s, _ := minimalTestService(t)
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
-	s.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(st)
+	require.NoError(t, err)
+	s.genesisTime = time.Now().Add(-sg)
 
 	require.NoError(t, s.checkSaveHotStateDB(t.Context()))
 	assert.LogsContain(t, hook, "Entering mode to save hot states in DB")
@@ -331,7 +336,9 @@ func TestCheckSaveHotStateDB_Disabling(t *testing.T) {
 	s, _ := minimalTestService(t)
 
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
-	s.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(st)
+	require.NoError(t, err)
+	s.genesisTime = time.Now().Add(-sg)
 	require.NoError(t, s.checkSaveHotStateDB(t.Context()))
 	s.genesisTime = time.Now()
 
@@ -352,7 +359,9 @@ func TestHandleCaches_EnablingLargeSize(t *testing.T) {
 	hook := logTest.NewGlobal()
 	s, _ := minimalTestService(t)
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
-	s.SetGenesisTime(time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second))
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(st)
+	require.NoError(t, err)
+	s.genesisTime = time.Now().Add(-sg)
 
 	helpers.ClearCache()
 	require.NoError(t, s.handleCaches())
@@ -364,7 +373,9 @@ func TestHandleCaches_DisablingLargeSize(t *testing.T) {
 	s, _ := minimalTestService(t)
 
 	st := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(epochsSinceFinalitySaveHotStateDB))
-	s.genesisTime = time.Now().Add(time.Duration(-1*int64(st)*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second)
+	sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(st)
+	require.NoError(t, err)
+	s.genesisTime = time.Now().Add(-sg)
 	require.NoError(t, s.handleCaches())
 	s.genesisTime = time.Now()
 

beacon-chain/blockchain/receive_data_column.go

@@ -17,7 +17,7 @@ func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataC
 // ReceiveDataColumn receives a single data column.
 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

@@ -12,11 +12,9 @@ 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"
@@ -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_forchoice.go

@@ -20,7 +20,7 @@ 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 +30,24 @@ 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)
 }

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)

beacon-chain/blockchain/setup_test.go

@@ -30,6 +30,8 @@ import (
 	"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/time/slots"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -54,6 +56,7 @@ type mockBroadcaster struct {
 
 type mockAccessor struct {
 	mockBroadcaster
+	mockCustodyManager
 	p2pTesting.MockPeerManager
 }
 
@@ -87,7 +90,7 @@ func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
-func (mb *mockBroadcaster) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+func (mb *mockBroadcaster) BroadcastDataColumnSidecar(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
 	mb.broadcastCalled = true
 	return nil
 }
@@ -97,6 +100,43 @@ 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
@@ -112,7 +152,9 @@ type testServiceRequirements struct {
 
 func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceRequirements) {
 	ctx := t.Context()
-	genesis := time.Now().Add(-1 * 4 * time.Duration(params.BeaconConfig().SlotsPerEpoch*primitives.Slot(params.BeaconConfig().SecondsPerSlot)) * time.Second) // Genesis was 4 epochs ago.
+	since, err := params.BeaconConfig().SlotSchedule.SinceGenesis(slots.UnsafeEpochStart(4))
+	require.NoError(t, err)
+	genesis := time.Now().Add(-since)
 	beaconDB := testDB.SetupDB(t)
 	fcs := doublylinkedtree.New()
 	fcs.SetGenesisTime(genesis)

beacon-chain/blockchain/testing/mock.go

@@ -430,7 +430,7 @@ func (s *ChainService) CurrentSlot() primitives.Slot {
 	if s.Slot != nil {
 		return *s.Slot
 	}
-	return primitives.Slot(uint64(time.Now().Unix()-s.Genesis.Unix()) / params.BeaconConfig().SecondsPerSlot)
+	return params.BeaconConfig().SlotSchedule.CurrentSlot(s.Genesis)
 }
 
 // Participation mocks the same method in the chain service.

beacon-chain/builder/service.go

@@ -25,6 +25,7 @@ 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.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)
@@ -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

@@ -24,21 +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
-	BlobBundleV2          *v1.BlobsBundleV2
-	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.
@@ -115,3 +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/subnet_ids.go

@@ -32,7 +32,20 @@ func newSubnetIDs() *subnetIDs {
 	cacheSize := int(params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().MaxCommitteesPerSlot * 2)) // lint:ignore uintcast -- constant values that would panic on startup if negative.
 	attesterCache := lruwrpr.New(cacheSize)
 	aggregatorCache := lruwrpr.New(cacheSize)
-	epochDuration := time.Duration(params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().SecondsPerSlot))
+	// TODO: Handle persistant cache subscription lengths to change.
+	// Wait... since the this is a default cache TTL, can we set it at runtime and always provide the current TTL when putting things in the cache?
+
+	// Calculate epoch duration considering variable slot durations
+	// Use current time to determine appropriate epoch duration
+	schedule := params.BeaconConfig().SlotSchedule
+	currentSlot := schedule.CurrentSlot(time.Unix(0, 0)) // Using zero genesis for now
+	slotsPerEpoch := uint64(params.BeaconConfig().SlotsPerEpoch)
+
+	epochDuration := time.Duration(0)
+	for i := uint64(0); i < slotsPerEpoch; i++ {
+		epochDuration += schedule.SlotDuration(currentSlot + primitives.Slot(i))
+	}
+
 	subLength := epochDuration * time.Duration(params.BeaconConfig().EpochsPerRandomSubnetSubscription)
 	persistentCache := cache.New(subLength*time.Second, epochDuration*time.Second)
 	return &subnetIDs{attester: attesterCache, aggregator: aggregatorCache, persistentSubnets: persistentCache}

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/cache/sync_subnet_ids.go

@@ -21,7 +21,9 @@ type syncSubnetIDs struct {
 var SyncSubnetIDs = newSyncSubnetIDs()
 
 func newSyncSubnetIDs() *syncSubnetIDs {
-	epochDuration := time.Duration(params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().SecondsPerSlot))
+	// TODO: Handle persistant cache subscription lengths to change.
+	// Wait... since the this is a default cache TTL, can we set it at runtime and always provide the current TTL when putting things in the cache?
+	epochDuration := time.Duration(params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().SlotSchedule.SlotDuration(0))))
 	// Set the default duration of a sync subnet index as the whole sync committee period.
 	subLength := epochDuration * time.Duration(params.BeaconConfig().EpochsPerSyncCommitteePeriod)
 	persistentCache := cache.New(subLength*time.Second, epochDuration*time.Second)

beacon-chain/core/altair/BUILD.bazel

@@ -84,7 +84,6 @@ go_test(
         "//testing/fuzz:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
-        "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_google_gofuzz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",

beacon-chain/core/altair/sync_committee_test.go

@@ -15,7 +15,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	prysmTime "github.com/OffchainLabs/prysm/v6/time"
 )
 
 func TestSyncCommitteeIndices_CanGet(t *testing.T) {
@@ -309,32 +308,45 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot == current_slot",
 			args: args{
 				syncMessageSlot: 15,
-				genesisTime:     prysmTime.Now().Add(-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 		},
 		{
 			name: "sync_message.slot == current_slot, received in middle of slot",
 			args: args{
 				syncMessageSlot: 15,
-				genesisTime: prysmTime.Now().Add(
-					-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(-(time.Duration(params.BeaconConfig().SecondsPerSlot/2) * time.Second)),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					sd := params.BeaconConfig().SlotSchedule.SlotDuration(15)
+					return time.Now().Add(-1 * sg).Add(-1 * (sd / 2))
+				}(),
 			},
 		},
 		{
 			name: "sync_message.slot == current_slot, received 200ms early",
 			args: args{
 				syncMessageSlot: 16,
-				genesisTime: prysmTime.Now().Add(
-					-16 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(-200 * time.Millisecond),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(16)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(-1 * 200 * time.Millisecond)
+				}(),
 			},
 		},
 		{
 			name: "sync_message.slot > current_slot",
 			args: args{
 				syncMessageSlot: 16,
-				genesisTime:     prysmTime.Now().Add(-(15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 			wantedErr: "(message slot 16) not within allowable range of",
 		},
@@ -342,15 +354,23 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot == current_slot+CLOCK_DISPARITY",
 			args: args{
 				syncMessageSlot: 100,
-				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second - params.BeaconConfig().MaximumGossipClockDisparityDuration())),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(-1 * params.BeaconConfig().MaximumGossipClockDisparityDuration())
+				}(),
 			},
 			wantedErr: "",
 		},
 		{
-			name: "sync_message.slot == current_slot+CLOCK_DISPARITY-1000ms",
+			name: "sync_message.slot == current_slot+CLOCK_DISPARITY-1001ms",
 			args: args{
 				syncMessageSlot: 100,
-				genesisTime:     prysmTime.Now().Add(-(100 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second) + params.BeaconConfig().MaximumGossipClockDisparityDuration() + 1000*time.Millisecond),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(-1 * params.BeaconConfig().MaximumGossipClockDisparityDuration()).Add(1001 * time.Millisecond)
+				}(),
 			},
 			wantedErr: "(message slot 100) not within allowable range of",
 		},
@@ -358,7 +378,11 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot == current_slot-CLOCK_DISPARITY",
 			args: args{
 				syncMessageSlot: 100,
-				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second + params.BeaconConfig().MaximumGossipClockDisparityDuration())),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(params.BeaconConfig().MaximumGossipClockDisparityDuration())
+				}(),
 			},
 			wantedErr: "",
 		},
@@ -366,7 +390,11 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot > current_slot+CLOCK_DISPARITY",
 			args: args{
 				syncMessageSlot: 101,
-				genesisTime:     prysmTime.Now().Add(-(100*time.Duration(params.BeaconConfig().SecondsPerSlot)*time.Second + params.BeaconConfig().MaximumGossipClockDisparityDuration())),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(-1 * params.BeaconConfig().MaximumGossipClockDisparityDuration())
+				}(),
 			},
 			wantedErr: "(message slot 101) not within allowable range of",
 		},
@@ -374,7 +402,11 @@ func Test_ValidateSyncMessageTime(t *testing.T) {
 			name: "sync_message.slot is well beyond current slot",
 			args: args{
 				syncMessageSlot: 1 << 32,
-				genesisTime:     prysmTime.Now().Add(-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 			wantedErr: "which exceeds max allowed value relative to the local clock",
 		},

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/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/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
 		}
 

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

@@ -84,7 +84,6 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
-        "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_stretchr_testify//require:go_default_library",

beacon-chain/core/helpers/attestation_test.go

@@ -13,7 +13,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
-	prysmTime "github.com/OffchainLabs/prysm/v6/time"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 )
 
@@ -127,98 +126,137 @@ func Test_ValidateAttestationTime(t *testing.T) {
 		{
 			name: "attestation.slot == current_slot",
 			args: args{
-				attSlot:     15,
-				genesisTime: prysmTime.Now().Add(-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 15,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot == current_slot, received in middle of slot",
 			args: args{
 				attSlot: 15,
-				genesisTime: prysmTime.Now().Add(
-					-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(-(time.Duration(params.BeaconConfig().SecondsPerSlot/2) * time.Second)),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					dur := params.BeaconConfig().SlotSchedule.SlotDuration(15)
+					return time.Now().Add(-1 * sg).Add(-1 * dur / 2)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot == current_slot, received 200ms early",
 			args: args{
 				attSlot: 16,
-				genesisTime: prysmTime.Now().Add(
-					-16 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(-200 * time.Millisecond),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(16)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(-200 * time.Millisecond)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot > current_slot",
 			args: args{
-				attSlot:     16,
-				genesisTime: prysmTime.Now().Add(-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 16,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 			wantedErr: "not within attestation propagation range",
 		},
 		{
 			name: "attestation.slot < current_slot-ATTESTATION_PROPAGATION_SLOT_RANGE",
 			args: args{
-				attSlot:     100 - params.BeaconConfig().AttestationPropagationSlotRange - 1,
-				genesisTime: prysmTime.Now().Add(-100 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 100 - params.BeaconConfig().AttestationPropagationSlotRange - 1,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 			wantedErr: "not within attestation propagation range",
 		},
 		{
 			name: "attestation.slot = current_slot-ATTESTATION_PROPAGATION_SLOT_RANGE",
 			args: args{
-				attSlot:     100 - params.BeaconConfig().AttestationPropagationSlotRange,
-				genesisTime: prysmTime.Now().Add(-100 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 100 - params.BeaconConfig().AttestationPropagationSlotRange,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot = current_slot-ATTESTATION_PROPAGATION_SLOT_RANGE, received 200ms late",
 			args: args{
 				attSlot: 100 - params.BeaconConfig().AttestationPropagationSlotRange,
-				genesisTime: prysmTime.Now().Add(
-					-100 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(200 * time.Millisecond),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(100)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(200 * time.Millisecond)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot < current_slot-ATTESTATION_PROPAGATION_SLOT_RANGE in deneb",
 			args: args{
-				attSlot:     300 - params.BeaconConfig().AttestationPropagationSlotRange - 1,
-				genesisTime: prysmTime.Now().Add(-300 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 300 - params.BeaconConfig().AttestationPropagationSlotRange - 1,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(300)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot = current_slot-ATTESTATION_PROPAGATION_SLOT_RANGE in deneb",
 			args: args{
-				attSlot:     300 - params.BeaconConfig().AttestationPropagationSlotRange,
-				genesisTime: prysmTime.Now().Add(-300 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 300 - params.BeaconConfig().AttestationPropagationSlotRange,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(300)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot = current_slot-ATTESTATION_PROPAGATION_SLOT_RANGE, received 200ms late in deneb",
 			args: args{
 				attSlot: 300 - params.BeaconConfig().AttestationPropagationSlotRange,
-				genesisTime: prysmTime.Now().Add(
-					-300 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(200 * time.Millisecond),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(300)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(200 * time.Millisecond)
+				}(),
 			},
 		},
 		{
 			name: "attestation.slot != current epoch or previous epoch in deneb",
 			args: args{
 				attSlot: 300 - params.BeaconConfig().AttestationPropagationSlotRange,
-				genesisTime: prysmTime.Now().Add(
-					-500 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second,
-				).Add(200 * time.Millisecond),
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(500)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg).Add(200 * time.Millisecond)
+				}(),
 			},
 			wantedErr: "attestation epoch 8 not within current epoch 15 or previous epoch",
 		},
 		{
 			name: "attestation.slot is well beyond current slot",
 			args: args{
-				attSlot:     1024,
-				genesisTime: time.Now().Add(-15 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second),
+				attSlot: 1024,
+				genesisTime: func() time.Time {
+					sg, err := params.BeaconConfig().SlotSchedule.SinceGenesis(15)
+					require.NoError(t, err)
+					return time.Now().Add(-1 * sg)
+				}(),
 			},
 			wantedErr: "attestation slot 1024 not within attestation propagation range of 0 to 15 (current slot)",
 		},
@@ -242,8 +280,9 @@ func TestVerifyCheckpointEpoch_Ok(t *testing.T) {
 	helpers.ClearCache()
 
 	// Genesis was 6 epochs ago exactly.
-	offset := params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().SecondsPerSlot * 6)
-	genesis := time.Now().Add(-1 * time.Second * time.Duration(offset))
+	offset, err := params.BeaconConfig().SlotSchedule.SinceGenesis(params.BeaconConfig().SlotsPerEpoch.Mul(6))
+	require.NoError(t, err)
+	genesis := time.Now().Add(-1 * offset)
 	assert.Equal(t, true, helpers.VerifyCheckpointEpoch(&ethpb.Checkpoint{Epoch: 6}, genesis))
 	assert.Equal(t, true, helpers.VerifyCheckpointEpoch(&ethpb.Checkpoint{Epoch: 5}, genesis))
 	assert.Equal(t, false, helpers.VerifyCheckpointEpoch(&ethpb.Checkpoint{Epoch: 4}, genesis))

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/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/light-client/BUILD.bazel

@@ -10,8 +10,12 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client",
     visibility = ["//visibility:public"],
     deps = [
+        "//async/event:go_default_library",
+        "//beacon-chain/core/feed:go_default_library",
+        "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/db/iface:go_default_library",
         "//beacon-chain/execution:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -39,6 +43,9 @@ go_test(
     ],
     deps = [
         ":go_default_library",
+        "//async/event:go_default_library",
+        "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types:go_default_library",

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

@@ -750,7 +750,9 @@ func UpdateHasSupermajority(syncAggregate *pb.SyncAggregate) bool {
 	return numActiveParticipants*3 >= maxActiveParticipants*2
 }
 
-func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
+// IsFinalityUpdateValidForBroadcast checks if a finality update needs to be broadcasted.
+// It is also used to check if an incoming gossiped finality update is valid for forwarding and saving.
+func IsFinalityUpdateValidForBroadcast(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
 	if oldUpdate == nil {
 		return true
 	}
@@ -772,6 +774,35 @@ func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityU
 	return true
 }
 
+// IsBetterFinalityUpdate checks if the new finality update is better than the old one for saving.
+// This does not concern broadcasting, but rather the decision of whether to save the new update.
+// For broadcasting checks, use IsFinalityUpdateValidForBroadcast.
+func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
+	if oldUpdate == nil {
+		return true
+	}
+
+	// Full nodes SHOULD provide the LightClientFinalityUpdate with the highest attested_header.beacon.slot (if multiple, highest signature_slot)
+	newFinalizedSlot := newUpdate.FinalizedHeader().Beacon().Slot
+	newAttestedSlot := newUpdate.AttestedHeader().Beacon().Slot
+
+	oldFinalizedSlot := oldUpdate.FinalizedHeader().Beacon().Slot
+	oldAttestedSlot := oldUpdate.AttestedHeader().Beacon().Slot
+
+	if newFinalizedSlot < oldFinalizedSlot {
+		return false
+	}
+	if newFinalizedSlot == oldFinalizedSlot {
+		if newAttestedSlot < oldAttestedSlot {
+			return false
+		}
+		if newAttestedSlot == oldAttestedSlot && newUpdate.SignatureSlot() <= oldUpdate.SignatureSlot() {
+			return false
+		}
+	}
+	return true
+}
+
 func IsBetterOptimisticUpdate(newUpdate, oldUpdate interfaces.LightClientOptimisticUpdate) bool {
 	if oldUpdate == nil {
 		return true

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

@@ -4,7 +4,11 @@ import (
 	"context"
 	"sync"
 
+	"github.com/OffchainLabs/prysm/v6/async/event"
+	"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/db/iface"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
@@ -16,13 +20,17 @@ type Store struct {
 	mu sync.RWMutex
 
 	beaconDB             iface.HeadAccessDatabase
-	lastFinalityUpdate   interfaces.LightClientFinalityUpdate
-	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate
+	lastFinalityUpdate   interfaces.LightClientFinalityUpdate   // tracks the best finality update seen so far
+	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate // tracks the best optimistic update seen so far
+	p2p                  p2p.Accessor
+	stateFeed            event.SubscriberSender
 }
 
-func NewLightClientStore(db iface.HeadAccessDatabase) *Store {
+func NewLightClientStore(db iface.HeadAccessDatabase, p p2p.Accessor, e event.SubscriberSender) *Store {
 	return &Store{
-		beaconDB: db,
+		beaconDB:  db,
+		p2p:       p,
+		stateFeed: e,
 	}
 }
 
@@ -143,10 +151,23 @@ func (s *Store) SaveLightClientUpdate(ctx context.Context, period uint64, update
 	return nil
 }
 
-func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate) {
+func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate, broadcast bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+
+	if broadcast && IsFinalityUpdateValidForBroadcast(update, s.lastFinalityUpdate) {
+		if err := s.p2p.BroadcastLightClientFinalityUpdate(context.Background(), update); err != nil {
+			log.WithError(err).Error("Could not broadcast light client finality update")
+		}
+	}
+
 	s.lastFinalityUpdate = update
+	log.Debug("Saved new light client finality update")
+
+	s.stateFeed.Send(&feed.Event{
+		Type: statefeed.LightClientFinalityUpdate,
+		Data: update,
+	})
 }
 
 func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
@@ -155,10 +176,23 @@ func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
 	return s.lastFinalityUpdate
 }
 
-func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate) {
+func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate, broadcast bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+
+	if broadcast {
+		if err := s.p2p.BroadcastLightClientOptimisticUpdate(context.Background(), update); err != nil {
+			log.WithError(err).Error("Could not broadcast light client optimistic update")
+		}
+	}
+
 	s.lastOptimisticUpdate = update
+	log.Debug("Saved new light client optimistic update")
+
+	s.stateFeed.Send(&feed.Event{
+		Type: statefeed.LightClientOptimisticUpdate,
+		Data: update,
+	})
 }
 
 func (s *Store) LastOptimisticUpdate() interfaces.LightClientOptimisticUpdate {

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

@@ -3,7 +3,10 @@ package light_client_test
 import (
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/async/event"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -21,7 +24,7 @@ func TestLightClientStore(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 
 	// Initialize the light client store
-	lcStore := &lightClient.Store{}
+	lcStore := lightClient.NewLightClientStore(testDB.SetupDB(t), &p2pTesting.FakeP2P{}, new(event.Feed))
 
 	// Create test light client updates for Capella and Deneb
 	lCapella := util.NewTestLightClient(t, version.Capella)
@@ -45,24 +48,118 @@ func TestLightClientStore(t *testing.T) {
 	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
 
 	// Set and get finality with Capella update. Optimistic update should be nil
-	lcStore.SetLastFinalityUpdate(finUpdateCapella)
+	lcStore.SetLastFinalityUpdate(finUpdateCapella, false)
 	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)
+	lcStore.SetLastOptimisticUpdate(opUpdateCapella, false)
 	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)
+	lcStore.SetLastFinalityUpdate(finUpdateDeneb, false)
+	lcStore.SetLastOptimisticUpdate(opUpdateDeneb, false)
 	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")
+}
+
+func TestLightClientStore_SetLastFinalityUpdate(t *testing.T) {
+	p2p := p2pTesting.NewTestP2P(t)
+	lcStore := lightClient.NewLightClientStore(testDB.SetupDB(t), p2p, new(event.Feed))
+
+	// update 0 with basic data and no supermajority following an empty lastFinalityUpdate - should save and broadcast
+	l0 := util.NewTestLightClient(t, version.Altair)
+	update0, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l0.Ctx, l0.State, l0.Block, l0.AttestedState, l0.AttestedBlock, l0.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update0, lcStore.LastFinalityUpdate()), "update0 should be better than nil")
+	// update0 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update0, lcStore.LastFinalityUpdate()), "update0 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update0, true)
+	require.Equal(t, update0, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after setting a new last finality update when previous is nil")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 1 with same finality slot, increased attested slot, and no supermajority - should save but not broadcast
+	l1 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(1))
+	update1, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l1.Ctx, l1.State, l1.Block, l1.AttestedState, l1.AttestedBlock, l1.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update1, update0), "update1 should be better than update0")
+	// update1 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update1, lcStore.LastFinalityUpdate()), "update1 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update1, true)
+	require.Equal(t, update1, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called after setting a new last finality update without supermajority")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 2 with same finality slot, increased attested slot, and supermajority - should save and broadcast
+	l2 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(2), util.WithSupermajority())
+	update2, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l2.Ctx, l2.State, l2.Block, l2.AttestedState, l2.AttestedBlock, l2.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update2, update1), "update2 should be better than update1")
+	// update2 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update2, lcStore.LastFinalityUpdate()), "update2 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update2, true)
+	require.Equal(t, update2, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after setting a new last finality update with supermajority")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 3 with same finality slot, increased attested slot, and supermajority - should save but not broadcast
+	l3 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(3), util.WithSupermajority())
+	update3, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l3.Ctx, l3.State, l3.Block, l3.AttestedState, l3.AttestedBlock, l3.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update3, update2), "update3 should be better than update2")
+	// update3 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update3, lcStore.LastFinalityUpdate()), "update3 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update3, true)
+	require.Equal(t, update3, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been when previous was already broadcast")
+
+	// update 4 with increased finality slot, increased attested slot, and supermajority - should save and broadcast
+	l4 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(1), util.WithSupermajority())
+	update4, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l4.Ctx, l4.State, l4.Block, l4.AttestedState, l4.AttestedBlock, l4.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update4, update3), "update4 should be better than update3")
+	// update4 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update4, lcStore.LastFinalityUpdate()), "update4 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update4, true)
+	require.Equal(t, update4, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after a new finality update with increased finality slot")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 5 with the same new finality slot, increased attested slot, and supermajority - should save but not broadcast
+	l5 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(2), util.WithSupermajority())
+	update5, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l5.Ctx, l5.State, l5.Block, l5.AttestedState, l5.AttestedBlock, l5.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update5, update4), "update5 should be better than update4")
+	// update5 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update5, lcStore.LastFinalityUpdate()), "update5 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update5, true)
+	require.Equal(t, update5, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called when previous was already broadcast with supermajority")
+
+	// update 6 with the same new finality slot, increased attested slot, and no supermajority - should save but not broadcast
+	l6 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(3))
+	update6, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l6.Ctx, l6.State, l6.Block, l6.AttestedState, l6.AttestedBlock, l6.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update6, update5), "update6 should be better than update5")
+	// update6 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update6, lcStore.LastFinalityUpdate()), "update6 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update6, true)
+	require.Equal(t, update6, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called when previous was already broadcast with supermajority")
 }

beacon-chain/core/peerdas/BUILD.bazel

@@ -16,7 +16,6 @@ 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",
@@ -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

@@ -31,15 +31,8 @@ var (
 	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) {
 	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
 
@@ -102,7 +95,7 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 }
 
 // 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()
 	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
@@ -127,7 +120,7 @@ func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 // 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/v1.6.0-alpha.3/specs/fulu/validator.md#get_data_column_sidecars_from_block
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block
 func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
 	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
 		return nil, nil
@@ -176,19 +169,6 @@ 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
@@ -219,7 +199,7 @@ func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
 // 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.)
-// https://github.com/ethereum/consensus-specs/blob/v1.6.0-alpha.3/specs/fulu/validator.md#get_data_column_sidecars
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars
 func dataColumnsSidecars(
 	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
 	blobKzgCommitments [][]byte,
@@ -243,6 +223,14 @@ func dataColumnsSidecars(
 			cellsForRow := cellsAndProofs[rowIndex].Cells
 			proofsForRow := cellsAndProofs[rowIndex].Proofs
 
+			// Validate that we have enough cells and proofs for this column index
+			if columnIndex >= uint64(len(cellsForRow)) {
+				return nil, errors.Errorf("column index %d exceeds cells length %d for blob %d", columnIndex, len(cellsForRow), rowIndex)
+			}
+			if columnIndex >= uint64(len(proofsForRow)) {
+				return nil, errors.Errorf("column index %d exceeds proofs length %d for blob %d", columnIndex, len(proofsForRow), rowIndex)
+			}
+
 			cell := cellsForRow[columnIndex]
 			column = append(column, cell)
 

beacon-chain/core/peerdas/das_core_test.go

@@ -67,6 +67,55 @@ func TestDataColumnSidecars(t *testing.T) {
 		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
 		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.
+		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
+		require.ErrorContains(t, "column index", err)
+		require.ErrorContains(t, "exceeds cells length", err)
+	})
+
+	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.
+		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
+		require.ErrorContains(t, "column index", err)
+		require.ErrorContains(t, "exceeds proofs length", err)
+	})
 }
 
 func TestComputeCustodyGroupForColumn(t *testing.T) {
@@ -104,62 +153,6 @@ 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/reconstruction.go

@@ -18,8 +18,8 @@ var (
 	ErrBlobsCellsProofsMismatch = errors.New("blobs and cells proofs mismatch")
 )
 
-// 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
@@ -58,7 +58,7 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 
 	// 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
 	}
 

beacon-chain/core/peerdas/reconstruction_test.go

@@ -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)
 	})

beacon-chain/core/peerdas/validator.go

@@ -8,7 +8,7 @@ import (
 )
 
 // 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 {

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"],

beacon-chain/core/signing/signature.go

@@ -1,34 +0,0 @@
-package signing
-
-import (
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/pkg/errors"
-)
-
-var ErrNilRegistration = errors.New("nil signed registration")
-
-// VerifyRegistrationSignature verifies the signature of a validator's registration.
-func VerifyRegistrationSignature(
-	sr *ethpb.SignedValidatorRegistrationV1,
-) error {
-	if sr == nil || sr.Message == nil {
-		return ErrNilRegistration
-	}
-
-	d := params.BeaconConfig().DomainApplicationBuilder
-	// Per spec, we want the fork version and genesis validator to be nil.
-	// Which is genesis value and zero by default.
-	sd, err := ComputeDomain(
-		d,
-		nil, /* fork version */
-		nil /* genesis val root */)
-	if err != nil {
-		return err
-	}
-
-	if err := VerifySigningRoot(sr.Message, sr.Message.Pubkey, sr.Signature, sd); err != nil {
-		return ErrSigFailedToVerify
-	}
-	return nil
-}

beacon-chain/core/signing/signature_test.go

@@ -1,42 +0,0 @@
-package signing_test
-
-import (
-	"testing"
-	"time"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/crypto/bls"
-	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/OffchainLabs/prysm/v6/testing/require"
-)
-
-func TestVerifyRegistrationSignature(t *testing.T) {
-	sk, err := bls.RandKey()
-	require.NoError(t, err)
-	reg := &ethpb.ValidatorRegistrationV1{
-		FeeRecipient: bytesutil.PadTo([]byte("fee"), 20),
-		GasLimit:     123456,
-		Timestamp:    uint64(time.Now().Unix()),
-		Pubkey:       sk.PublicKey().Marshal(),
-	}
-	d := params.BeaconConfig().DomainApplicationBuilder
-	domain, err := signing.ComputeDomain(d, nil, nil)
-	require.NoError(t, err)
-	sr, err := signing.ComputeSigningRoot(reg, domain)
-	require.NoError(t, err)
-	sk.Sign(sr[:]).Marshal()
-
-	sReg := &ethpb.SignedValidatorRegistrationV1{
-		Message:   reg,
-		Signature: sk.Sign(sr[:]).Marshal(),
-	}
-	require.NoError(t, signing.VerifyRegistrationSignature(sReg))
-
-	sReg.Signature = []byte("bad")
-	require.ErrorIs(t, signing.VerifyRegistrationSignature(sReg), signing.ErrSigFailedToVerify)
-
-	sReg.Message = nil
-	require.ErrorIs(t, signing.VerifyRegistrationSignature(sReg), signing.ErrNilRegistration)
-}

beacon-chain/das/BUILD.bazel

@@ -4,7 +4,6 @@ go_library(
     name = "go_default_library",
     srcs = [
         "availability_blobs.go",
-        "availability_columns.go",
         "blob_cache.go",
         "data_column_cache.go",
         "iface.go",
@@ -13,7 +12,6 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/das",
     visibility = ["//visibility:public"],
     deps = [
-        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -23,7 +21,6 @@ go_library(
         "//runtime/logging:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -33,16 +30,13 @@ go_test(
     name = "go_default_test",
     srcs = [
         "availability_blobs_test.go",
-        "availability_columns_test.go",
         "blob_cache_test.go",
         "data_column_cache_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
-        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification: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",
@@ -51,7 +45,6 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/das/availability_blobs.go

@@ -53,30 +53,25 @@ func NewLazilyPersistentStore(store *filesystem.BlobStorage, verifier BlobBatchV
 // Persist adds blobs to the working blob cache. Blobs stored in this cache will be persisted
 // for at least as long as the node is running. Once IsDataAvailable succeeds, all blobs referenced
 // by the given block are guaranteed to be persisted for the remainder of the retention period.
-func (s *LazilyPersistentStoreBlob) Persist(current primitives.Slot, sidecars ...blocks.ROSidecar) error {
+func (s *LazilyPersistentStoreBlob) Persist(current primitives.Slot, sidecars ...blocks.ROBlob) error {
 	if len(sidecars) == 0 {
 		return nil
 	}
 
-	blobSidecars, err := blocks.BlobSidecarsFromSidecars(sidecars)
-	if err != nil {
-		return errors.Wrap(err, "blob sidecars from sidecars")
-	}
-
-	if len(blobSidecars) > 1 {
-		firstRoot := blobSidecars[0].BlockRoot()
-		for _, sidecar := range blobSidecars[1:] {
+	if len(sidecars) > 1 {
+		firstRoot := sidecars[0].BlockRoot()
+		for _, sidecar := range sidecars[1:] {
 			if sidecar.BlockRoot() != firstRoot {
 				return errMixedRoots
 			}
 		}
 	}
-	if !params.WithinDAPeriod(slots.ToEpoch(blobSidecars[0].Slot()), slots.ToEpoch(current)) {
+	if !params.WithinDAPeriod(slots.ToEpoch(sidecars[0].Slot()), slots.ToEpoch(current)) {
 		return nil
 	}
-	key := keyFromSidecar(blobSidecars[0])
+	key := keyFromSidecar(sidecars[0])
 	entry := s.cache.ensure(key)
-	for _, blobSidecar := range blobSidecars {
+	for _, blobSidecar := range sidecars {
 		if err := entry.stash(&blobSidecar); err != nil {
 			return err
 		}

beacon-chain/das/availability_blobs_test.go

@@ -118,23 +118,21 @@ func TestLazilyPersistent_Missing(t *testing.T) {
 
 	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
 
-	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
-
 	mbv := &mockBlobBatchVerifier{t: t, scs: blobSidecars}
 	as := NewLazilyPersistentStore(store, mbv)
 
 	// Only one commitment persisted, should return error with other indices
-	require.NoError(t, as.Persist(1, scs[2]))
+	require.NoError(t, as.Persist(1, blobSidecars[2]))
 	err := as.IsDataAvailable(ctx, 1, blk)
 	require.ErrorIs(t, err, errMissingSidecar)
 
 	// All but one persisted, return missing idx
-	require.NoError(t, as.Persist(1, scs[0]))
+	require.NoError(t, as.Persist(1, blobSidecars[0]))
 	err = as.IsDataAvailable(ctx, 1, blk)
 	require.ErrorIs(t, err, errMissingSidecar)
 
 	// All persisted, return nil
-	require.NoError(t, as.Persist(1, scs...))
+	require.NoError(t, as.Persist(1, blobSidecars...))
 
 	require.NoError(t, as.IsDataAvailable(ctx, 1, blk))
 }
@@ -149,10 +147,8 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 	blobSidecars[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
 	as := NewLazilyPersistentStore(store, mbv)
 
-	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
-
 	// Only one commitment persisted, should return error with other indices
-	require.NoError(t, as.Persist(1, scs[0]))
+	require.NoError(t, as.Persist(1, blobSidecars[0]))
 	err := as.IsDataAvailable(ctx, 1, blk)
 	require.NotNil(t, err)
 	require.ErrorIs(t, err, errCommitmentMismatch)
@@ -161,29 +157,25 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 func TestLazyPersistOnceCommitted(t *testing.T) {
 	_, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 6)
 
-	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
-
 	as := NewLazilyPersistentStore(filesystem.NewEphemeralBlobStorage(t), &mockBlobBatchVerifier{})
 	// stashes as expected
-	require.NoError(t, as.Persist(1, scs...))
+	require.NoError(t, as.Persist(1, blobSidecars...))
 	// ignores duplicates
-	require.ErrorIs(t, as.Persist(1, scs...), ErrDuplicateSidecar)
+	require.ErrorIs(t, as.Persist(1, blobSidecars...), ErrDuplicateSidecar)
 
 	// ignores index out of bound
 	blobSidecars[0].Index = 6
-	require.ErrorIs(t, as.Persist(1, blocks.NewSidecarFromBlobSidecar(blobSidecars[0])), errIndexOutOfBounds)
+	require.ErrorIs(t, as.Persist(1, blobSidecars[0]), errIndexOutOfBounds)
 
 	_, moreBlobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 4)
 
-	more := blocks.NewSidecarsFromBlobSidecars(moreBlobSidecars)
-
 	// ignores sidecars before the retention period
 	slotOOB, err := slots.EpochStart(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest)
 	require.NoError(t, err)
-	require.NoError(t, as.Persist(32+slotOOB, more[0]))
+	require.NoError(t, as.Persist(32+slotOOB, moreBlobSidecars[0]))
 
 	// doesn't ignore new sidecars with a different block root
-	require.NoError(t, as.Persist(1, more...))
+	require.NoError(t, as.Persist(1, moreBlobSidecars...))
 }
 
 type mockBlobBatchVerifier struct {

beacon-chain/das/availability_columns.go

@@ -1,208 +0,0 @@
-package das
-
-import (
-	"context"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
-	"github.com/OffchainLabs/prysm/v6/time/slots"
-	"github.com/ethereum/go-ethereum/p2p/enode"
-	errors "github.com/pkg/errors"
-)
-
-// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
-// This implementation will hold any data columns passed to Persist until the IsDataAvailable is called for their
-// block, at which time they will undergo full verification and be saved to the disk.
-type LazilyPersistentStoreColumn struct {
-	store                  *filesystem.DataColumnStorage
-	nodeID                 enode.ID
-	cache                  *dataColumnCache
-	custodyInfo            *peerdas.CustodyInfo
-	newDataColumnsVerifier verification.NewDataColumnsVerifier
-}
-
-var _ AvailabilityStore = &LazilyPersistentStoreColumn{}
-
-// DataColumnsVerifier enables LazilyPersistentStoreColumn to manage the verification process
-// going from RODataColumn->VerifiedRODataColumn, while avoiding the decision of which individual verifications
-// to run and in what order. Since LazilyPersistentStoreColumn always tries to verify and save data columns only when
-// they are all available, the interface takes a slice of data column sidecars.
-type DataColumnsVerifier interface {
-	VerifiedRODataColumns(ctx context.Context, blk blocks.ROBlock, scs []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error)
-}
-
-// NewLazilyPersistentStoreColumn creates a new LazilyPersistentStoreColumn.
-// WARNING: The resulting LazilyPersistentStoreColumn is NOT thread-safe.
-func NewLazilyPersistentStoreColumn(store *filesystem.DataColumnStorage, nodeID enode.ID, newDataColumnsVerifier verification.NewDataColumnsVerifier, custodyInfo *peerdas.CustodyInfo) *LazilyPersistentStoreColumn {
-	return &LazilyPersistentStoreColumn{
-		store:                  store,
-		nodeID:                 nodeID,
-		cache:                  newDataColumnCache(),
-		custodyInfo:            custodyInfo,
-		newDataColumnsVerifier: newDataColumnsVerifier,
-	}
-}
-
-// PersistColumns adds columns to the working column cache. Columns stored in this cache will be persisted
-// for at least as long as the node is running. Once IsDataAvailable succeeds, all columns referenced
-// by the given block are guaranteed to be persisted for the remainder of the retention period.
-func (s *LazilyPersistentStoreColumn) Persist(current primitives.Slot, sidecars ...blocks.ROSidecar) error {
-	if len(sidecars) == 0 {
-		return nil
-	}
-
-	dataColumnSidecars, err := blocks.DataColumnSidecarsFromSidecars(sidecars)
-	if err != nil {
-		return errors.Wrap(err, "blob sidecars from sidecars")
-	}
-
-	// It is safe to retrieve the first sidecar.
-	firstSidecar := dataColumnSidecars[0]
-
-	if len(sidecars) > 1 {
-		firstRoot := firstSidecar.BlockRoot()
-		for _, sidecar := range dataColumnSidecars[1:] {
-			if sidecar.BlockRoot() != firstRoot {
-				return errMixedRoots
-			}
-		}
-	}
-
-	firstSidecarEpoch, currentEpoch := slots.ToEpoch(firstSidecar.Slot()), slots.ToEpoch(current)
-	if !params.WithinDAPeriod(firstSidecarEpoch, currentEpoch) {
-		return nil
-	}
-
-	key := cacheKey{slot: firstSidecar.Slot(), root: firstSidecar.BlockRoot()}
-	entry := s.cache.ensure(key)
-
-	for _, sidecar := range dataColumnSidecars {
-		if err := entry.stash(&sidecar); err != nil {
-			return errors.Wrap(err, "stash DataColumnSidecar")
-		}
-	}
-
-	return nil
-}
-
-// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
-// DataColumnsSidecars already in the db are assumed to have been previously verified against the block.
-func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, currentSlot primitives.Slot, block blocks.ROBlock) error {
-	blockCommitments, err := s.fullCommitmentsToCheck(s.nodeID, block, currentSlot)
-	if err != nil {
-		return errors.Wrapf(err, "full commitments to check with block root `%#x` and current slot `%d`", block.Root(), currentSlot)
-	}
-
-	// Return early for blocks that do not have any commitments.
-	if blockCommitments.count() == 0 {
-		return nil
-	}
-
-	// Get the root of the block.
-	blockRoot := block.Root()
-
-	// Build the cache key for the block.
-	key := cacheKey{slot: block.Block().Slot(), root: blockRoot}
-
-	// Retrieve the cache entry for the block, or create an empty one if it doesn't exist.
-	entry := s.cache.ensure(key)
-
-	// Delete the cache entry for the block at the end.
-	defer s.cache.delete(key)
-
-	// Set the disk summary for the block in the cache entry.
-	entry.setDiskSummary(s.store.Summary(blockRoot))
-
-	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
-	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
-	// ignore their response and decrease their peer score.
-	roDataColumns, err := entry.filter(blockRoot, blockCommitments)
-	if err != nil {
-		return errors.Wrap(err, "entry filter")
-	}
-
-	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
-	verifier := s.newDataColumnsVerifier(roDataColumns, verification.ByRangeRequestDataColumnSidecarRequirements)
-
-	if err := verifier.ValidFields(); err != nil {
-		return errors.Wrap(err, "valid fields")
-	}
-
-	if err := verifier.SidecarInclusionProven(); err != nil {
-		return errors.Wrap(err, "sidecar inclusion proven")
-	}
-
-	if err := verifier.SidecarKzgProofVerified(); err != nil {
-		return errors.Wrap(err, "sidecar KZG proof verified")
-	}
-
-	verifiedRoDataColumns, err := verifier.VerifiedRODataColumns()
-	if err != nil {
-		return errors.Wrap(err, "verified RO data columns - should never happen")
-	}
-
-	if err := s.store.Save(verifiedRoDataColumns); err != nil {
-		return errors.Wrap(err, "save data column sidecars")
-	}
-
-	return nil
-}
-
-// fullCommitmentsToCheck returns the commitments to check for a given block.
-func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, block blocks.ROBlock, currentSlot primitives.Slot) (*safeCommitmentsArray, error) {
-	// Return early for blocks that are pre-Fulu.
-	if block.Version() < version.Fulu {
-		return &safeCommitmentsArray{}, nil
-	}
-
-	// Compute the block epoch.
-	blockSlot := block.Block().Slot()
-	blockEpoch := slots.ToEpoch(blockSlot)
-
-	// Compute the current epoch.
-	currentEpoch := slots.ToEpoch(currentSlot)
-
-	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.
-	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
-		return &safeCommitmentsArray{}, nil
-	}
-
-	// Retrieve the KZG commitments for the block.
-	kzgCommitments, err := block.Block().Body().BlobKzgCommitments()
-	if err != nil {
-		return nil, errors.Wrap(err, "blob KZG commitments")
-	}
-
-	// Return early if there are no commitments in the block.
-	if len(kzgCommitments) == 0 {
-		return &safeCommitmentsArray{}, nil
-	}
-
-	// Retrieve the groups count.
-	custodyGroupCount := s.custodyInfo.ActualGroupCount()
-
-	// Retrieve peer info.
-	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
-	if err != nil {
-		return nil, errors.Wrap(err, "peer info")
-	}
-
-	// Create a safe commitments array for the custody columns.
-	commitmentsArray := &safeCommitmentsArray{}
-	commitmentsArraySize := uint64(len(commitmentsArray))
-
-	for column := range peerInfo.CustodyColumns {
-		if column >= commitmentsArraySize {
-			return nil, errors.Errorf("custody column index %d too high (max allowed %d) - should never happen", column, commitmentsArraySize)
-		}
-
-		commitmentsArray[column] = kzgCommitments
-	}
-
-	return commitmentsArray, nil
-}

beacon-chain/das/availability_columns_test.go

@@ -1,319 +0,0 @@
-package das
-
-import (
-	"context"
-	"testing"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
-	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
-	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"
-	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
-	"github.com/OffchainLabs/prysm/v6/time/slots"
-	"github.com/ethereum/go-ethereum/p2p/enode"
-)
-
-var commitments = [][]byte{
-	bytesutil.PadTo([]byte("a"), 48),
-	bytesutil.PadTo([]byte("b"), 48),
-	bytesutil.PadTo([]byte("c"), 48),
-	bytesutil.PadTo([]byte("d"), 48),
-}
-
-func TestPersist(t *testing.T) {
-	t.Run("no sidecars", func(t *testing.T) {
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
-		err := lazilyPersistentStoreColumns.Persist(0)
-		require.NoError(t, err)
-		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
-	})
-
-	t.Run("mixed roots", func(t *testing.T) {
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-
-		dataColumnParamsByBlockRoot := []util.DataColumnParam{
-			{Slot: 1, Index: 1},
-			{Slot: 2, Index: 2},
-		}
-
-		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
-
-		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
-		require.ErrorIs(t, err, errMixedRoots)
-		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
-	})
-
-	t.Run("outside DA period", func(t *testing.T) {
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-
-		dataColumnParamsByBlockRoot := []util.DataColumnParam{
-			{Slot: 1, Index: 1},
-		}
-
-		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
-
-		err := lazilyPersistentStoreColumns.Persist(1_000_000, roSidecars...)
-		require.NoError(t, err)
-		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
-	})
-
-	t.Run("nominal", func(t *testing.T) {
-		const slot = 42
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-
-		dataColumnParamsByBlockRoot := []util.DataColumnParam{
-			{Slot: slot, Index: 1},
-			{Slot: slot, Index: 5},
-		}
-
-		roSidecars, roDataColumns := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
-
-		err := lazilyPersistentStoreColumns.Persist(slot, roSidecars...)
-		require.NoError(t, err)
-		require.Equal(t, 1, len(lazilyPersistentStoreColumns.cache.entries))
-
-		key := cacheKey{slot: slot, root: roDataColumns[0].BlockRoot()}
-		entry, ok := lazilyPersistentStoreColumns.cache.entries[key]
-		require.Equal(t, true, ok)
-
-		// A call to Persist does NOT save the sidecars to disk.
-		require.Equal(t, uint64(0), entry.diskSummary.Count())
-
-		require.DeepSSZEqual(t, roDataColumns[0], *entry.scs[1])
-		require.DeepSSZEqual(t, roDataColumns[1], *entry.scs[5])
-
-		for i, roDataColumn := range entry.scs {
-			if map[int]bool{1: true, 5: true}[i] {
-				continue
-			}
-
-			require.IsNil(t, roDataColumn)
-		}
-	})
-}
-
-func TestIsDataAvailable(t *testing.T) {
-	newDataColumnsVerifier := func(dataColumnSidecars []blocks.RODataColumn, _ []verification.Requirement) verification.DataColumnsVerifier {
-		return &mockDataColumnsVerifier{t: t, dataColumnSidecars: dataColumnSidecars}
-	}
-
-	ctx := t.Context()
-
-	t.Run("without commitments", func(t *testing.T) {
-		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
-		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
-
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
-
-		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
-		require.NoError(t, err)
-	})
-
-	t.Run("with commitments", func(t *testing.T) {
-		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
-		signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
-		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
-		block := signedRoBlock.Block()
-		slot := block.Slot()
-		proposerIndex := block.ProposerIndex()
-		parentRoot := block.ParentRoot()
-		stateRoot := block.StateRoot()
-		bodyRoot, err := block.Body().HashTreeRoot()
-		require.NoError(t, err)
-
-		root := signedRoBlock.Root()
-
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
-
-		indices := [...]uint64{1, 17, 87, 102}
-		dataColumnsParams := make([]util.DataColumnParam, 0, len(indices))
-		for _, index := range indices {
-			dataColumnParams := util.DataColumnParam{
-				Index:          index,
-				KzgCommitments: commitments,
-
-				Slot:          slot,
-				ProposerIndex: proposerIndex,
-				ParentRoot:    parentRoot[:],
-				StateRoot:     stateRoot[:],
-				BodyRoot:      bodyRoot[:],
-			}
-
-			dataColumnsParams = append(dataColumnsParams, dataColumnParams)
-		}
-
-		_, verifiedRoDataColumns := util.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnsParams)
-
-		key := cacheKey{root: root}
-		entry := lazilyPersistentStoreColumns.cache.ensure(key)
-		defer lazilyPersistentStoreColumns.cache.delete(key)
-
-		for _, verifiedRoDataColumn := range verifiedRoDataColumns {
-			err := entry.stash(&verifiedRoDataColumn.RODataColumn)
-			require.NoError(t, err)
-		}
-
-		err = lazilyPersistentStoreColumns.IsDataAvailable(ctx, slot, signedRoBlock)
-		require.NoError(t, err)
-
-		actual, err := dataColumnStorage.Get(root, indices[:])
-		require.NoError(t, err)
-
-		summary := dataColumnStorage.Summary(root)
-		require.Equal(t, uint64(len(indices)), summary.Count())
-		require.DeepSSZEqual(t, verifiedRoDataColumns, actual)
-	})
-}
-
-func TestFullCommitmentsToCheck(t *testing.T) {
-	windowSlots, err := slots.EpochEnd(params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest)
-	require.NoError(t, err)
-
-	testCases := []struct {
-		name        string
-		commitments [][]byte
-		block       func(*testing.T) blocks.ROBlock
-		slot        primitives.Slot
-	}{
-		{
-			name: "Pre-Fulu block",
-			block: func(t *testing.T) blocks.ROBlock {
-				return newSignedRoBlock(t, util.NewBeaconBlockElectra())
-			},
-		},
-		{
-			name: "Commitments outside data availability window",
-			block: func(t *testing.T) blocks.ROBlock {
-				beaconBlockElectra := util.NewBeaconBlockElectra()
-
-				// Block is from slot 0, "current slot" is window size +1 (so outside the window)
-				beaconBlockElectra.Block.Body.BlobKzgCommitments = commitments
-
-				return newSignedRoBlock(t, beaconBlockElectra)
-			},
-			slot: windowSlots + 1,
-		},
-		{
-			name: "Commitments within data availability window",
-			block: func(t *testing.T) blocks.ROBlock {
-				signedBeaconBlockFulu := util.NewBeaconBlockFulu()
-				signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
-				signedBeaconBlockFulu.Block.Slot = 100
-
-				return newSignedRoBlock(t, signedBeaconBlockFulu)
-			},
-			commitments: commitments,
-			slot:        100,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			resetFlags := flags.Get()
-			gFlags := new(flags.GlobalFlags)
-			gFlags.SubscribeAllDataSubnets = true
-			flags.Init(gFlags)
-			defer flags.Init(resetFlags)
-
-			b := tc.block(t)
-			s := NewLazilyPersistentStoreColumn(nil, enode.ID{}, nil, &peerdas.CustodyInfo{})
-
-			commitmentsArray, err := s.fullCommitmentsToCheck(enode.ID{}, b, tc.slot)
-			require.NoError(t, err)
-
-			for _, commitments := range commitmentsArray {
-				require.DeepEqual(t, tc.commitments, commitments)
-			}
-		})
-	}
-}
-
-func roSidecarsFromDataColumnParamsByBlockRoot(t *testing.T, parameters []util.DataColumnParam) ([]blocks.ROSidecar, []blocks.RODataColumn) {
-	roDataColumns, _ := util.CreateTestVerifiedRoDataColumnSidecars(t, parameters)
-
-	roSidecars := make([]blocks.ROSidecar, 0, len(roDataColumns))
-	for _, roDataColumn := range roDataColumns {
-		roSidecars = append(roSidecars, blocks.NewSidecarFromDataColumnSidecar(roDataColumn))
-	}
-
-	return roSidecars, roDataColumns
-}
-
-func newSignedRoBlock(t *testing.T, signedBeaconBlock interface{}) blocks.ROBlock {
-	sb, err := blocks.NewSignedBeaconBlock(signedBeaconBlock)
-	require.NoError(t, err)
-
-	rb, err := blocks.NewROBlock(sb)
-	require.NoError(t, err)
-
-	return rb
-}
-
-type mockDataColumnsVerifier struct {
-	t                                                                        *testing.T
-	dataColumnSidecars                                                       []blocks.RODataColumn
-	validCalled, SidecarInclusionProvenCalled, SidecarKzgProofVerifiedCalled bool
-}
-
-var _ verification.DataColumnsVerifier = &mockDataColumnsVerifier{}
-
-func (m *mockDataColumnsVerifier) VerifiedRODataColumns() ([]blocks.VerifiedRODataColumn, error) {
-	require.Equal(m.t, true, m.validCalled && m.SidecarInclusionProvenCalled && m.SidecarKzgProofVerifiedCalled)
-
-	verifiedDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(m.dataColumnSidecars))
-	for _, dataColumnSidecar := range m.dataColumnSidecars {
-		verifiedDataColumnSidecar := blocks.NewVerifiedRODataColumn(dataColumnSidecar)
-		verifiedDataColumnSidecars = append(verifiedDataColumnSidecars, verifiedDataColumnSidecar)
-	}
-
-	return verifiedDataColumnSidecars, nil
-}
-
-func (m *mockDataColumnsVerifier) SatisfyRequirement(verification.Requirement) {}
-
-func (m *mockDataColumnsVerifier) ValidFields() error {
-	m.validCalled = true
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) CorrectSubnet(dataColumnSidecarSubTopic string, expectedTopics []string) error {
-	return nil
-}
-func (m *mockDataColumnsVerifier) NotFromFutureSlot() error                         { return nil }
-func (m *mockDataColumnsVerifier) SlotAboveFinalized() error                        { return nil }
-func (m *mockDataColumnsVerifier) ValidProposerSignature(ctx context.Context) error { return nil }
-
-func (m *mockDataColumnsVerifier) SidecarParentSeen(parentSeen func([fieldparams.RootLength]byte) bool) error {
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarParentValid(badParent func([fieldparams.RootLength]byte) bool) error {
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarParentSlotLower() error       { return nil }
-func (m *mockDataColumnsVerifier) SidecarDescendsFromFinalized() error { return nil }
-
-func (m *mockDataColumnsVerifier) SidecarInclusionProven() error {
-	m.SidecarInclusionProvenCalled = true
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarKzgProofVerified() error {
-	m.SidecarKzgProofVerifiedCalled = true
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarProposerExpected(ctx context.Context) error { return nil }

beacon-chain/das/blob_cache.go

@@ -99,20 +99,26 @@ func (e *blobCacheEntry) filter(root [32]byte, kc [][]byte, slot primitives.Slot
 		if e.diskSummary.HasIndex(i) {
 			continue
 		}
+		// Check if e.scs has this index before accessing
+		var sidecar *blocks.ROBlob
+		if i < uint64(len(e.scs)) {
+			sidecar = e.scs[i]
+		}
+
 		if kc[i] == nil {
-			if e.scs[i] != nil {
-				return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, no block commitment", root, i, e.scs[i].KzgCommitment)
+			if sidecar != nil {
+				return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, no block commitment", root, i, sidecar.KzgCommitment)
 			}
 			continue
 		}
 
-		if e.scs[i] == nil {
+		if sidecar == nil {
 			return nil, errors.Wrapf(errMissingSidecar, "root=%#x, index=%#x", root, i)
 		}
-		if !bytes.Equal(kc[i], e.scs[i].KzgCommitment) {
-			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, e.scs[i].KzgCommitment, kc[i])
+		if !bytes.Equal(kc[i], sidecar.KzgCommitment) {
+			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, sidecar.KzgCommitment, kc[i])
 		}
-		scs = append(scs, *e.scs[i])
+		scs = append(scs, *sidecar)
 	}
 
 	return scs, nil

beacon-chain/das/blob_cache_test.go

@@ -155,6 +155,41 @@ func TestFilter(t *testing.T) {
 			},
 			err: errCommitmentMismatch,
 		},
+		{
+			name: "empty scs array with commitments",
+			setup: func(t *testing.T) (*blobCacheEntry, [][]byte, []blocks.ROBlob) {
+				// This reproduces the panic condition where entry.scs is empty or nil
+				// but we have commitments to check
+				entry := &blobCacheEntry{
+					scs: nil, // Empty/nil array that caused the panic
+				}
+				// Create a commitment that would trigger the check at index 0
+				commits := [][]byte{
+					bytesutil.PadTo([]byte("commitment1"), 48),
+				}
+				return entry, commits, nil
+			},
+			err: errMissingSidecar,
+		},
+		{
+			name: "scs array shorter than commitments",
+			setup: func(t *testing.T) (*blobCacheEntry, [][]byte, []blocks.ROBlob) {
+				// This reproduces the condition where entry.scs exists but is shorter
+				// than the number of commitments we're checking
+				entry := &blobCacheEntry{
+					scs: make([]*blocks.ROBlob, 2), // Only 2 slots
+				}
+				// Create 4 commitments, accessing index 2 and 3 would have panicked
+				commits := [][]byte{
+					nil,
+					nil,
+					bytesutil.PadTo([]byte("commitment3"), 48),
+					bytesutil.PadTo([]byte("commitment4"), 48),
+				}
+				return entry, commits, nil
+			},
+			err: errMissingSidecar,
+		},
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {

beacon-chain/das/iface.go

@@ -15,5 +15,5 @@ import (
 // durably persisted before returning a non-error value.
 type AvailabilityStore interface {
 	IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
-	Persist(current primitives.Slot, sc ...blocks.ROSidecar) error
+	Persist(current primitives.Slot, blobSidecar ...blocks.ROBlob) error
 }

beacon-chain/das/mock.go

@@ -5,13 +5,12 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	errors "github.com/pkg/errors"
 )
 
 // MockAvailabilityStore is an implementation of AvailabilityStore that can be used by other packages in tests.
 type MockAvailabilityStore struct {
 	VerifyAvailabilityCallback func(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
-	PersistBlobsCallback       func(current primitives.Slot, sc ...blocks.ROBlob) error
+	PersistBlobsCallback       func(current primitives.Slot, blobSidecar ...blocks.ROBlob) error
 }
 
 var _ AvailabilityStore = &MockAvailabilityStore{}
@@ -25,13 +24,9 @@ func (m *MockAvailabilityStore) IsDataAvailable(ctx context.Context, current pri
 }
 
 // Persist satisfies the corresponding method of the AvailabilityStore interface in a way that is useful for tests.
-func (m *MockAvailabilityStore) Persist(current primitives.Slot, sc ...blocks.ROSidecar) error {
-	blobSidecars, err := blocks.BlobSidecarsFromSidecars(sc)
-	if err != nil {
-		return errors.Wrap(err, "blob sidecars from sidecars")
-	}
+func (m *MockAvailabilityStore) Persist(current primitives.Slot, blobSidecar ...blocks.ROBlob) error {
 	if m.PersistBlobsCallback != nil {
-		return m.PersistBlobsCallback(current, blobSidecars...)
+		return m.PersistBlobsCallback(current, blobSidecar...)
 	}
 	return nil
 }

beacon-chain/db/BUILD.bazel

@@ -13,6 +13,7 @@ go_library(
     visibility = [
         "//beacon-chain:__subpackages__",
         "//cmd/beacon-chain:__subpackages__",
+        "//genesis:__subpackages__",
         "//testing/slasher/simulator:__pkg__",
         "//tools:__subpackages__",
     ],

beacon-chain/db/alias.go

@@ -10,6 +10,11 @@ type ReadOnlyDatabase = iface.ReadOnlyDatabase
 // about head info. For head info, use github.com/prysmaticlabs/prysm/blockchain.HeadFetcher.
 type NoHeadAccessDatabase = iface.NoHeadAccessDatabase
 
+// ReadOnlyDatabaseWithSeqNum exposes Prysm's Ethereum data backend for read access only, no information about
+// head info, but with read/write access to the p2p metadata sequence number.
+// This is used for the p2p service.
+type ReadOnlyDatabaseWithSeqNum = iface.ReadOnlyDatabaseWithSeqNum
+
 // HeadAccessDatabase exposes Prysm's Ethereum backend for read/write access with information about
 // chain head information. This interface should be used sparingly as the HeadFetcher is the source
 // of truth around chain head information while this interface serves as persistent storage for the

beacon-chain/db/filesystem/data_column.go

@@ -100,6 +100,14 @@ type (
 	}
 )
 
+// DataColumnStorageReader is an interface to read data column sidecars from the filesystem.
+type DataColumnStorageReader interface {
+	Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary
+	Get(root [fieldparams.RootLength]byte, indices []uint64) ([]blocks.VerifiedRODataColumn, error)
+}
+
+var _ DataColumnStorageReader = &DataColumnStorage{}
+
 // WithDataColumnBasePath is a required option that sets the base path of data column storage.
 func WithDataColumnBasePath(base string) DataColumnStorageOption {
 	return func(b *DataColumnStorage) error {

beacon-chain/db/filesystem/data_column_cache.go

@@ -84,12 +84,6 @@ func (s DataColumnStorageSummary) Stored() map[uint64]bool {
 	return stored
 }
 
-// DataColumnStorageSummarizer can be used to receive a summary of metadata about data columns on disk for a given root.
-// The DataColumnStorageSummary can be used to check which indices (if any) are available for a given block by root.
-type DataColumnStorageSummarizer interface {
-	Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary
-}
-
 type dataColumnStorageSummaryCache struct {
 	mu                 sync.RWMutex
 	dataColumnCount    float64
@@ -98,8 +92,6 @@ type dataColumnStorageSummaryCache struct {
 	cache              map[[fieldparams.RootLength]byte]DataColumnStorageSummary
 }
 
-var _ DataColumnStorageSummarizer = &dataColumnStorageSummaryCache{}
-
 func newDataColumnStorageSummaryCache() *dataColumnStorageSummaryCache {
 	return &dataColumnStorageSummaryCache{
 		cache:             make(map[[fieldparams.RootLength]byte]DataColumnStorageSummary),

beacon-chain/db/filesystem/mock.go

@@ -144,14 +144,3 @@ func NewEphemeralDataColumnStorageWithMocker(t testing.TB) (*DataColumnMocker, *
 	fs, dcs := NewEphemeralDataColumnStorageAndFs(t)
 	return &DataColumnMocker{fs: fs, dcs: dcs}, dcs
 }
-
-func NewMockDataColumnStorageSummarizer(t *testing.T, set map[[fieldparams.RootLength]byte][]uint64) DataColumnStorageSummarizer {
-	c := newDataColumnStorageSummaryCache()
-	for root, indices := range set {
-		if err := c.set(DataColumnsIdent{Root: root, Epoch: 0, Indices: indices}); err != nil {
-			t.Fatal(err)
-		}
-	}
-
-	return c
-}

beacon-chain/db/iface/interface.go

@@ -33,6 +33,7 @@ type ReadOnlyDatabase interface {
 	IsFinalizedBlock(ctx context.Context, blockRoot [32]byte) bool
 	FinalizedChildBlock(ctx context.Context, blockRoot [32]byte) (interfaces.ReadOnlySignedBeaconBlock, error)
 	HighestRootsBelowSlot(ctx context.Context, slot primitives.Slot) (primitives.Slot, [][32]byte, error)
+	EarliestSlot(ctx context.Context) (primitives.Slot, error)
 	// State related methods.
 	State(ctx context.Context, blockRoot [32]byte) (state.BeaconState, error)
 	StateOrError(ctx context.Context, blockRoot [32]byte) (state.BeaconState, error)
@@ -56,14 +57,25 @@ type ReadOnlyDatabase interface {
 	// Fee recipients operations.
 	FeeRecipientByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (common.Address, error)
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
-	// light client operations
+	// Light client operations
 	LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]interfaces.LightClientUpdate, error)
 	LightClientUpdate(ctx context.Context, period uint64) (interfaces.LightClientUpdate, error)
 	LightClientBootstrap(ctx context.Context, blockRoot []byte) (interfaces.LightClientBootstrap, error)
-
-	// origin checkpoint sync support
+	// Origin checkpoint sync support
 	OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
 	BackfillStatus(context.Context) (*dbval.BackfillStatus, error)
+
+	// P2P Metadata operations.
+	MetadataSeqNum(ctx context.Context) (uint64, error)
+}
+
+// ReadOnlyDatabaseWithSeqNum defines a struct which has read access to database methods
+// and also has read/write access to the p2p metadata sequence number.
+// Only used for the p2p service.
+type ReadOnlyDatabaseWithSeqNum interface {
+	ReadOnlyDatabase
+
+	SaveMetadataSeqNum(ctx context.Context, seqNum uint64) error
 }
 
 // NoHeadAccessDatabase defines a struct without access to chain head data.
@@ -102,6 +114,24 @@ type NoHeadAccessDatabase interface {
 
 	CleanUpDirtyStates(ctx context.Context, slotsPerArchivedPoint primitives.Slot) error
 	DeleteHistoricalDataBeforeSlot(ctx context.Context, slot primitives.Slot, batchSize int) (int, error)
+
+	// Genesis operations.
+	LoadGenesis(ctx context.Context, stateBytes []byte) error
+	SaveGenesisData(ctx context.Context, state state.BeaconState) error
+	EnsureEmbeddedGenesis(ctx context.Context) error
+
+	// Support for checkpoint sync and backfill.
+	SaveOriginCheckpointBlockRoot(ctx context.Context, blockRoot [32]byte) error
+	SaveOrigin(ctx context.Context, serState, serBlock []byte) error
+	SaveBackfillStatus(context.Context, *dbval.BackfillStatus) error
+	BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error
+
+	// Custody operations.
+	UpdateSubscribedToAllDataSubnets(ctx context.Context, subscribed bool) (bool, error)
+	UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error)
+
+	// P2P Metadata operations.
+	SaveMetadataSeqNum(ctx context.Context, seqNum uint64) error
 }
 
 // HeadAccessDatabase defines a struct with access to reading chain head data.
@@ -112,16 +142,6 @@ type HeadAccessDatabase interface {
 	HeadBlock(ctx context.Context) (interfaces.ReadOnlySignedBeaconBlock, error)
 	HeadBlockRoot() ([32]byte, error)
 	SaveHeadBlockRoot(ctx context.Context, blockRoot [32]byte) error
-
-	// Genesis operations.
-	LoadGenesis(ctx context.Context, stateBytes []byte) error
-	SaveGenesisData(ctx context.Context, state state.BeaconState) error
-	EnsureEmbeddedGenesis(ctx context.Context) error
-
-	// Support for checkpoint sync and backfill.
-	SaveOrigin(ctx context.Context, serState, serBlock []byte) error
-	SaveBackfillStatus(context.Context, *dbval.BackfillStatus) error
-	BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error
 }
 
 // SlasherDatabase interface for persisting data related to detecting slashable offenses on Ethereum.

beacon-chain/db/kv/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "backup.go",
         "blocks.go",
         "checkpoint.go",
+        "custody.go",
         "deposit_contract.go",
         "encoding.go",
         "error.go",
@@ -23,6 +24,7 @@ go_library(
         "migration_block_slot_index.go",
         "migration_finalized_parent.go",
         "migration_state_validators.go",
+        "p2p.go",
         "schema.go",
         "state.go",
         "state_summary.go",
@@ -38,7 +40,6 @@ go_library(
         "//beacon-chain/db/filters:go_default_library",
         "//beacon-chain/db/iface:go_default_library",
         "//beacon-chain/state:go_default_library",
-        "//beacon-chain/state/genesis:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -50,6 +51,7 @@ go_library(
         "//container/slice:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz/detect:go_default_library",
+        "//genesis:go_default_library",
         "//io/file:go_default_library",
         "//monitoring/progress:go_default_library",
         "//monitoring/tracing:go_default_library",
@@ -83,6 +85,7 @@ go_test(
         "backup_test.go",
         "blocks_test.go",
         "checkpoint_test.go",
+        "custody_test.go",
         "deposit_contract_test.go",
         "encoding_test.go",
         "execution_chain_test.go",
@@ -94,6 +97,7 @@ go_test(
         "migration_archived_index_test.go",
         "migration_block_slot_index_test.go",
         "migration_state_validators_test.go",
+        "p2p_test.go",
         "state_summary_test.go",
         "state_test.go",
         "utils_test.go",
@@ -106,7 +110,6 @@ go_test(
         "//beacon-chain/db/filters:go_default_library",
         "//beacon-chain/db/iface:go_default_library",
         "//beacon-chain/state:go_default_library",
-        "//beacon-chain/state/genesis:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -116,6 +119,7 @@ go_test(
         "//consensus-types/light-client:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//genesis:go_default_library",
         "//proto/dbval:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",

beacon-chain/db/kv/blocks.go

@@ -860,6 +860,47 @@ func (s *Store) SaveRegistrationsByValidatorIDs(ctx context.Context, ids []primi
 	})
 }
 
+// EarliestStoredSlot returns the earliest slot in the database.
+func (s *Store) EarliestSlot(ctx context.Context) (primitives.Slot, error) {
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	_, span := trace.StartSpan(ctx, "BeaconDB.EarliestSlot")
+	defer span.End()
+
+	earliestAvailableSlot := primitives.Slot(0)
+	err := s.db.View(func(tx *bolt.Tx) error {
+		// Retrieve the root corresponding to the earliest available block.
+		c := tx.Bucket(blockSlotIndicesBucket).Cursor()
+		k, v := c.First()
+		if k == nil || v == nil {
+			return ErrNotFound
+		}
+		slot := bytesutil.BytesToSlotBigEndian(k)
+
+		// The genesis block may be indexed in this bucket, even if we started from a checkpoint.
+		// Because of this, we check the next block. If the next block is still in the genesis epoch,
+		// then we consider we have the whole chain.
+		if slot != 0 {
+			earliestAvailableSlot = slot
+		}
+
+		k, v = c.Next()
+		if k == nil || v == nil {
+			// Only the genesis block is available.
+			return nil
+		}
+		slot = bytesutil.BytesToSlotBigEndian(k)
+		if slot < slotsPerEpoch {
+			// We are still in the genesis epoch, so we consider we have the whole chain.
+			return nil
+		}
+
+		earliestAvailableSlot = slot
+		return nil
+	})
+
+	return earliestAvailableSlot, err
+}
+
 type slotRoot struct {
 	slot primitives.Slot
 	root [32]byte
@@ -883,7 +924,7 @@ func (s *Store) slotRootsInRange(ctx context.Context, start, end primitives.Slot
 		c := bkt.Cursor()
 		for k, v := c.Seek(key); ; /* rely on internal checks to exit */ k, v = c.Prev() {
 			if len(k) == 0 && len(v) == 0 {
-				// The `edge`` variable and this `if` deal with 2 edge cases:
+				// The `edge` variable and this `if` deal with 2 edge cases:
 				// - Seeking past the end of the bucket (the `end` param is higher than the highest slot).
 				// - Seeking before the beginning of the bucket (the `start` param is lower than the lowest slot).
 				// In both of these cases k,v will be nil and we can handle the same way using `edge` to

beacon-chain/db/kv/blocks_test.go

@@ -1,6 +1,7 @@
 package kv
 
 import (
+	"context"
 	"fmt"
 	"testing"
 	"time"
@@ -1327,3 +1328,86 @@ func TestStore_RegistrationsByValidatorID(t *testing.T) {
 	want := errors.Wrap(ErrNotFoundFeeRecipient, "validator id 3")
 	require.Equal(t, want.Error(), err.Error())
 }
+
+// Block creates a phase0 beacon block at the specified slot and saves it to the database.
+func createAndSaveBlock(t *testing.T, ctx context.Context, db *Store, slot primitives.Slot) {
+	block := util.NewBeaconBlock()
+	block.Block.Slot = slot
+
+	wrappedBlock, err := blocks.NewSignedBeaconBlock(block)
+	require.NoError(t, err)
+	require.NoError(t, db.SaveBlock(ctx, wrappedBlock))
+}
+
+func TestStore_EarliestSlot(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("empty database returns ErrNotFound", func(t *testing.T) {
+		db := setupDB(t)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.ErrorIs(t, err, ErrNotFound)
+		assert.Equal(t, primitives.Slot(0), slot)
+	})
+
+	t.Run("database with only genesis block", func(t *testing.T) {
+		db := setupDB(t)
+
+		// Create and save genesis block (slot 0)
+		createAndSaveBlock(t, ctx, db, 0)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, primitives.Slot(0), slot)
+	})
+
+	t.Run("database with genesis and blocks in genesis epoch", func(t *testing.T) {
+		db := setupDB(t)
+		slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+		// Create and save genesis block (slot 0)
+		createAndSaveBlock(t, ctx, db, 0)
+
+		// Create and save a block in the genesis epoch
+		createAndSaveBlock(t, ctx, db, primitives.Slot(slotsPerEpoch-1))
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, primitives.Slot(0), slot)
+	})
+
+	t.Run("database with genesis and blocks beyond genesis epoch", func(t *testing.T) {
+		db := setupDB(t)
+		slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+		// Create and save genesis block (slot 0)
+		createAndSaveBlock(t, ctx, db, 0)
+
+		// Create and save a block beyond the genesis epoch
+		nextEpochSlot := primitives.Slot(slotsPerEpoch)
+		createAndSaveBlock(t, ctx, db, nextEpochSlot)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, nextEpochSlot, slot)
+	})
+
+	t.Run("database starting from checkpoint (non-zero earliest slot)", func(t *testing.T) {
+		db := setupDB(t)
+		slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+		// Simulate starting from a checkpoint by creating blocks starting from a later slot
+		checkpointSlot := primitives.Slot(slotsPerEpoch * 10) // 10 epochs later
+		nextEpochSlot := checkpointSlot + slotsPerEpoch
+
+		// Create and save first block at checkpoint slot
+		createAndSaveBlock(t, ctx, db, checkpointSlot)
+
+		// Create and save another block in the next epoch
+		createAndSaveBlock(t, ctx, db, nextEpochSlot)
+
+		slot, err := db.EarliestSlot(ctx)
+		require.NoError(t, err)
+		assert.Equal(t, nextEpochSlot, slot)
+	})
+}

beacon-chain/db/kv/custody.go

@@ -0,0 +1,129 @@
+package kv
+
+import (
+	"context"
+
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	bolt "go.etcd.io/bbolt"
+)
+
+// UpdateCustodyInfo atomically updates the custody group count only it is greater than the stored one.
+// In this case, it also updates the earliest available slot with the provided value.
+// It returns the (potentially updated) custody group count and earliest available slot.
+func (s *Store) UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.UpdateCustodyInfo")
+	defer span.End()
+
+	storedGroupCount, storedEarliestAvailableSlot := uint64(0), primitives.Slot(0)
+	if err := s.db.Update(func(tx *bolt.Tx) error {
+		// Retrieve the custody bucket.
+		bucket, err := tx.CreateBucketIfNotExists(custodyBucket)
+		if err != nil {
+			return errors.Wrap(err, "create custody bucket")
+		}
+
+		// Retrieve the stored custody group count.
+		storedGroupCountBytes := bucket.Get(groupCountKey)
+		if len(storedGroupCountBytes) != 0 {
+			storedGroupCount = bytesutil.BytesToUint64BigEndian(storedGroupCountBytes)
+		}
+
+		// Retrieve the stored earliest available slot.
+		storedEarliestAvailableSlotBytes := bucket.Get(earliestAvailableSlotKey)
+		if len(storedEarliestAvailableSlotBytes) != 0 {
+			storedEarliestAvailableSlot = primitives.Slot(bytesutil.BytesToUint64BigEndian(storedEarliestAvailableSlotBytes))
+		}
+
+		// Exit early if the new custody group count is lower than or equal to the stored one.
+		if custodyGroupCount <= storedGroupCount {
+			return nil
+		}
+
+		storedGroupCount, storedEarliestAvailableSlot = custodyGroupCount, earliestAvailableSlot
+
+		// Store the earliest available slot.
+		bytes := bytesutil.Uint64ToBytesBigEndian(uint64(earliestAvailableSlot))
+		if err := bucket.Put(earliestAvailableSlotKey, bytes); err != nil {
+			return errors.Wrap(err, "put earliest available slot")
+		}
+
+		// Store the custody group count.
+		bytes = bytesutil.Uint64ToBytesBigEndian(custodyGroupCount)
+		if err := bucket.Put(groupCountKey, bytes); err != nil {
+			return errors.Wrap(err, "put custody group count")
+		}
+
+		return nil
+	}); err != nil {
+		return 0, 0, err
+	}
+
+	log.WithFields(logrus.Fields{
+		"earliestAvailableSlot": storedEarliestAvailableSlot,
+		"groupCount":            storedGroupCount,
+	}).Debug("Custody info")
+
+	return storedEarliestAvailableSlot, storedGroupCount, nil
+}
+
+// UpdateSubscribedToAllDataSubnets updates the "subscribed to all data subnets" status in the database
+// only if `subscribed` is `true`.
+// It returns the previous subscription status.
+func (s *Store) UpdateSubscribedToAllDataSubnets(ctx context.Context, subscribed bool) (bool, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.UpdateSubscribedToAllDataSubnets")
+	defer span.End()
+
+	result := false
+	if !subscribed {
+		if err := s.db.View(func(tx *bolt.Tx) error {
+			// Retrieve the custody bucket.
+			bucket := tx.Bucket(custodyBucket)
+			if bucket == nil {
+				return nil
+			}
+
+			// Retrieve the subscribe all data subnets flag.
+			bytes := bucket.Get(subscribeAllDataSubnetsKey)
+			if len(bytes) == 0 {
+				return nil
+			}
+
+			if bytes[0] == 1 {
+				result = true
+			}
+
+			return nil
+		}); err != nil {
+			return false, err
+		}
+
+		return result, nil
+	}
+
+	if err := s.db.Update(func(tx *bolt.Tx) error {
+		// Retrieve the custody bucket.
+		bucket, err := tx.CreateBucketIfNotExists(custodyBucket)
+		if err != nil {
+			return errors.Wrap(err, "create custody bucket")
+		}
+
+		bytes := bucket.Get(subscribeAllDataSubnetsKey)
+		if len(bytes) != 0 && bytes[0] == 1 {
+			result = true
+		}
+
+		if err := bucket.Put(subscribeAllDataSubnetsKey, []byte{1}); err != nil {
+			return errors.Wrap(err, "put subscribe all data subnets")
+		}
+
+		return nil
+	}); err != nil {
+		return false, err
+	}
+
+	return result, nil
+}

beacon-chain/db/kv/custody_test.go

@@ -0,0 +1,176 @@
+package kv
+
+import (
+	"context"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	bolt "go.etcd.io/bbolt"
+)
+
+// getCustodyInfoFromDB reads the custody info directly from the database for testing purposes.
+func getCustodyInfoFromDB(t *testing.T, db *Store) (primitives.Slot, uint64) {
+	t.Helper()
+	var earliestSlot primitives.Slot
+	var groupCount uint64
+
+	err := db.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(custodyBucket)
+		if bucket == nil {
+			return nil
+		}
+
+		// Read group count
+		groupCountBytes := bucket.Get(groupCountKey)
+		if len(groupCountBytes) != 0 {
+			groupCount = bytesutil.BytesToUint64BigEndian(groupCountBytes)
+		}
+
+		// Read earliest available slot
+		earliestSlotBytes := bucket.Get(earliestAvailableSlotKey)
+		if len(earliestSlotBytes) != 0 {
+			earliestSlot = primitives.Slot(bytesutil.BytesToUint64BigEndian(earliestSlotBytes))
+		}
+
+		return nil
+	})
+	require.NoError(t, err)
+
+	return earliestSlot, groupCount
+}
+
+// getSubscriptionStatusFromDB reads the subscription status directly from the database for testing purposes.
+func getSubscriptionStatusFromDB(t *testing.T, db *Store) bool {
+	t.Helper()
+	var subscribed bool
+
+	err := db.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(custodyBucket)
+		if bucket == nil {
+			return nil
+		}
+
+		bytes := bucket.Get(subscribeAllDataSubnetsKey)
+		if len(bytes) != 0 && bytes[0] == 1 {
+			subscribed = true
+		}
+
+		return nil
+	})
+	require.NoError(t, err)
+
+	return subscribed
+}
+
+func TestUpdateCustodyInfo(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("initial update with empty database", func(t *testing.T) {
+		const (
+			earliestSlot = primitives.Slot(100)
+			groupCount   = uint64(5)
+		)
+
+		db := setupDB(t)
+
+		slot, count, err := db.UpdateCustodyInfo(ctx, earliestSlot, groupCount)
+		require.NoError(t, err)
+		require.Equal(t, earliestSlot, slot)
+		require.Equal(t, groupCount, count)
+
+		storedSlot, storedCount := getCustodyInfoFromDB(t, db)
+		require.Equal(t, earliestSlot, storedSlot)
+		require.Equal(t, groupCount, storedCount)
+	})
+
+	t.Run("update with higher group count", func(t *testing.T) {
+		const (
+			initialSlot  = primitives.Slot(100)
+			initialCount = uint64(5)
+			earliestSlot = primitives.Slot(200)
+			groupCount   = uint64(10)
+		)
+
+		db := setupDB(t)
+
+		_, _, err := db.UpdateCustodyInfo(ctx, initialSlot, initialCount)
+		require.NoError(t, err)
+
+		slot, count, err := db.UpdateCustodyInfo(ctx, earliestSlot, groupCount)
+		require.NoError(t, err)
+		require.Equal(t, earliestSlot, slot)
+		require.Equal(t, groupCount, count)
+
+		storedSlot, storedCount := getCustodyInfoFromDB(t, db)
+		require.Equal(t, earliestSlot, storedSlot)
+		require.Equal(t, groupCount, storedCount)
+	})
+
+	t.Run("update with lower group count should not update", func(t *testing.T) {
+		const (
+			initialSlot  = primitives.Slot(200)
+			initialCount = uint64(10)
+			earliestSlot = primitives.Slot(300)
+			groupCount   = uint64(8)
+		)
+
+		db := setupDB(t)
+
+		_, _, err := db.UpdateCustodyInfo(ctx, initialSlot, initialCount)
+		require.NoError(t, err)
+
+		slot, count, err := db.UpdateCustodyInfo(ctx, earliestSlot, groupCount)
+		require.NoError(t, err)
+		require.Equal(t, initialSlot, slot)
+		require.Equal(t, initialCount, count)
+
+		storedSlot, storedCount := getCustodyInfoFromDB(t, db)
+		require.Equal(t, initialSlot, storedSlot)
+		require.Equal(t, initialCount, storedCount)
+	})
+}
+
+func TestUpdateSubscribedToAllDataSubnets(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("initial update with empty database - set to false", func(t *testing.T) {
+		db := setupDB(t)
+
+		prev, err := db.UpdateSubscribedToAllDataSubnets(ctx, false)
+		require.NoError(t, err)
+		require.Equal(t, false, prev)
+
+		stored := getSubscriptionStatusFromDB(t, db)
+		require.Equal(t, false, stored)
+	})
+
+	t.Run("attempt to update from true to false (should not change)", func(t *testing.T) {
+		db := setupDB(t)
+
+		_, err := db.UpdateSubscribedToAllDataSubnets(ctx, true)
+		require.NoError(t, err)
+
+		prev, err := db.UpdateSubscribedToAllDataSubnets(ctx, false)
+		require.NoError(t, err)
+		require.Equal(t, true, prev)
+
+		stored := getSubscriptionStatusFromDB(t, db)
+		require.Equal(t, true, stored)
+	})
+
+	t.Run("attempt to update from true to false (should not change)", func(t *testing.T) {
+		db := setupDB(t)
+
+		_, err := db.UpdateSubscribedToAllDataSubnets(ctx, true)
+		require.NoError(t, err)
+
+		prev, err := db.UpdateSubscribedToAllDataSubnets(ctx, true)
+		require.NoError(t, err)
+		require.Equal(t, true, prev)
+
+		stored := getSubscriptionStatusFromDB(t, db)
+		require.Equal(t, true, stored)
+	})
+}

beacon-chain/db/kv/error.go

@@ -19,6 +19,9 @@ var ErrNotFoundGenesisBlockRoot = errors.Wrap(ErrNotFound, "OriginGenesisRoot")
 // ErrNotFoundFeeRecipient is a not found error specifically for the fee recipient getter
 var ErrNotFoundFeeRecipient = errors.Wrap(ErrNotFound, "fee recipient")
 
+// ErrNotFoundMetadataSeqNum is a not found error specifically for the metadata sequence number getter
+var ErrNotFoundMetadataSeqNum = errors.Wrap(ErrNotFound, "metadata sequence number")
+
 var errEmptyBlockSlice = errors.New("[]blocks.ROBlock is empty")
 var errIncorrectBlockParent = errors.New("unexpected missing or forked blocks in a []ROBlock")
 var errFinalizedChildNotFound = errors.New("unable to find finalized root descending from backfill batch")

beacon-chain/db/kv/genesis.go

@@ -8,6 +8,7 @@ import (
 	dbIface "github.com/OffchainLabs/prysm/v6/beacon-chain/db/iface"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/encoding/ssz/detect"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/pkg/errors"
 )
@@ -97,8 +98,22 @@ func (s *Store) EnsureEmbeddedGenesis(ctx context.Context) error {
 	if err != nil {
 		return err
 	}
-	if gs != nil && !gs.IsNil() {
+	if !state.IsNil(gs) {
 		return s.SaveGenesisData(ctx, gs)
 	}
 	return nil
 }
+
+type LegacyGenesisProvider struct {
+	store *Store
+}
+
+func NewLegacyGenesisProvider(store *Store) *LegacyGenesisProvider {
+	return &LegacyGenesisProvider{store: store}
+}
+
+var _ genesis.Provider = &LegacyGenesisProvider{}
+
+func (p *LegacyGenesisProvider) Genesis(ctx context.Context) (state.BeaconState, error) {
+	return p.store.LegacyGenesisState(ctx)
+}

beacon-chain/db/kv/genesis_test.go

@@ -4,10 +4,12 @@ import (
 	"encoding/hex"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/iface"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -145,13 +147,17 @@ func TestEnsureEmbeddedGenesis(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	// Embedded Genesis works with Mainnet config
 	cfg := params.MainnetConfig()
-	cfg.SecondsPerSlot = 1
+	cfg.SlotSchedule = &params.SlotSchedule{{
+		Epoch:        0,
+		SlotDuration: 1 * time.Second,
+	}}
 	undo, err := params.SetActiveWithUndo(cfg)
 	require.NoError(t, err)
 	defer func() {
 		require.NoError(t, undo())
 	}()
 
+	genesis.StoreEmbeddedDuringTest(t, params.BeaconConfig().ConfigName)
 	ctx := t.Context()
 	db := setupDB(t)
 

beacon-chain/db/kv/kv.go

@@ -123,6 +123,7 @@ var Buckets = [][]byte{
 
 	feeRecipientBucket,
 	registrationBucket,
+	custodyBucket,
 }
 
 // KVStoreOption is a functional option that modifies a kv.Store.

beacon-chain/db/kv/p2p.go

@@ -0,0 +1,42 @@
+package kv
+
+import (
+	"context"
+
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
+	bolt "go.etcd.io/bbolt"
+)
+
+// MetadataSeqNum retrieves the p2p metadata sequence number from the database.
+// It returns 0 and ErrNotFoundMetadataSeqNum if the key does not exist.
+func (s *Store) MetadataSeqNum(ctx context.Context) (uint64, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.MetadataSeqNum")
+	defer span.End()
+
+	var seqNum uint64
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(chainMetadataBucket)
+		val := bkt.Get(metadataSequenceNumberKey)
+		if val == nil {
+			return ErrNotFoundMetadataSeqNum
+		}
+
+		seqNum = bytesutil.BytesToUint64BigEndian(val)
+		return nil
+	})
+
+	return seqNum, err
+}
+
+// SaveMetadataSeqNum saves the p2p metadata sequence number to the database.
+func (s *Store) SaveMetadataSeqNum(ctx context.Context, seqNum uint64) error {
+	_, span := trace.StartSpan(ctx, "BeaconDB.SaveMetadataSeqNum")
+	defer span.End()
+
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(chainMetadataBucket)
+		val := bytesutil.Uint64ToBytesBigEndian(seqNum)
+		return bkt.Put(metadataSequenceNumberKey, val)
+	})
+}

beacon-chain/db/kv/p2p_test.go

@@ -0,0 +1,33 @@
+package kv
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestStore_MetadataSeqNum(t *testing.T) {
+	ctx := t.Context()
+	db := setupDB(t)
+
+	seqNum, err := db.MetadataSeqNum(ctx)
+	require.ErrorIs(t, err, ErrNotFoundMetadataSeqNum)
+	assert.Equal(t, uint64(0), seqNum)
+
+	initialSeqNum := uint64(42)
+	err = db.SaveMetadataSeqNum(ctx, initialSeqNum)
+	require.NoError(t, err)
+
+	retrievedSeqNum, err := db.MetadataSeqNum(ctx)
+	require.NoError(t, err)
+	assert.Equal(t, initialSeqNum, retrievedSeqNum)
+
+	updatedSeqNum := uint64(43)
+	err = db.SaveMetadataSeqNum(ctx, updatedSeqNum)
+	require.NoError(t, err)
+
+	retrievedSeqNum, err = db.MetadataSeqNum(ctx)
+	require.NoError(t, err)
+	assert.Equal(t, updatedSeqNum, retrievedSeqNum)
+}