Files
consensus-specs/specs/lightclient/lightclient-fork.md
Hsiao-Wei Wang acfe49e3f3 executable light client patch: beacon-chain.md (#2141)
* Bump remerkleable to 0.1.18

* Disable `sync-protocol.md` for now. Make linter pass

* Enable lightclient tests

* Use *new* `optional_fast_aggregate_verify`

* Fix ToC and codespell

* Do not run phase1 tests with Lightclient patch

* Fix the Eth1Data casting bug. Add a workaround.

* Fix `run_on_attestation` testing helper

* Revert

* Rename `optional_fast_aggregate_verify` to `eth2_fast_aggregate_verify`

* Apply Proto's suggestion

* Apply Danny's suggestion

* Fixing tests

* Fix after rebasing

* Rename `LIGHTCLIENT` -> `LIGHTCLIENT_PATCH`

* New doctoc

* Add lightclient patch configs

* fix gitignore light client patch generator output

* Upgrade state for light client patch

* Add `lightclient-fork.md` to deal the fork boundary and fix
`process_block_header`

* Misc cleanups

1) Add a summary note for every function that is changed.
2) Avoid changing `process_block` (instead only change `process_block_header`).
3) Rename `G2_INFINITY_POINT_SIG` to `G2_POINT_AT_INFINITY` to avoid `SIG` contraction.
4) Misc cleanups

* Update block.py

* Update beacon-chain.md

* Fix typo "minimal" -> "mainnet"

Co-authored-by: Marin Petrunić <mpetrunic@users.noreply.github.com>

* Use the new `BeaconBlockHeader` instead of phase 0 version

* Update config files

* Move `sync_committee_bits` and `sync_committee_signature` back to `BeaconBlockBody`

Co-authored-by: protolambda <proto@protolambda.com>
Co-authored-by: Justin <drakefjustin@gmail.com>
Co-authored-by: Marin Petrunić <mpetrunic@users.noreply.github.com>
2020-12-15 13:18:20 +08:00

3.1 KiB

Ethereum 2.0 Light Client Support -- From Phase 0 to Light Client Patch

Notice: This document is a work-in-progress for researchers and implementers.

Table of contents

Introduction

This document describes the process of moving from Phase 0 to Phase 1 of Ethereum 2.0.

Configuration

Warning: this configuration is not definitive.

Name Value
LIGHTCLIENT_PATCH_FORK_VERSION Version('0x01000000')
LIGHTCLIENT_PATCH_FORK_SLOT Slot(0) TBD

Fork to Light-client patch

Fork trigger

TBD. Social consensus, along with state conditions such as epoch boundary, finality, deposits, active validator count, etc. may be part of the decision process to trigger the fork. For now we assume the condition will be triggered at slot LIGHTCLIENT_PATCH_FORK_SLOT, where LIGHTCLIENT_PATCH_FORK_SLOT % SLOTS_PER_EPOCH == 0.

Upgrading the state

After process_slots of Phase 0 finishes, if state.slot == LIGHTCLIENT_PATCH_FORK_SLOT, an irregular state change is made to upgrade to light-client patch.

def upgrade_to_lightclient_patch(pre: phase0.BeaconState) -> BeaconState:
    epoch = get_current_epoch(pre)
    post = BeaconState(
        genesis_time=pre.genesis_time,
        slot=pre.slot,
        fork=Fork(
            previous_version=pre.fork.current_version,
            current_version=LIGHTCLIENT_PATCH_FORK_VERSION,
            epoch=epoch,
        ),
        # History
        latest_block_header=pre.latest_block_header,
        block_roots=pre.block_roots,
        state_roots=pre.state_roots,
        historical_roots=pre.historical_roots,
        # Eth1
        eth1_data=pre.eth1_data,
        eth1_data_votes=pre.eth1_data_votes,
        eth1_deposit_index=pre.eth1_deposit_index,
        # Registry
        validators=pre.validators,
        balances=pre.balances,
        # Randomness
        randao_mixes=pre.randao_mixes,
        # Slashings
        slashings=pre.slashings,
        # Attestations
        # previous_epoch_attestations is cleared on upgrade. 
        previous_epoch_attestations=List[PendingAttestation, MAX_ATTESTATIONS * SLOTS_PER_EPOCH](),
        # empty in pre state, since the upgrade is performed just after an epoch boundary.
        current_epoch_attestations=List[PendingAttestation, MAX_ATTESTATIONS * SLOTS_PER_EPOCH](),
        # Finality
        justification_bits=pre.justification_bits,
        previous_justified_checkpoint=pre.previous_justified_checkpoint,
        current_justified_checkpoint=pre.current_justified_checkpoint,
        finalized_checkpoint=pre.finalized_checkpoint,
        # Light-client
        current_sync_committee=SyncCommittee(),
        next_sync_committee=SyncCommittee(),
    )
    return post