eth2.0-specs/specs/core/1_phase1_fork.md

4.2 KiB

Ethereum 2.0 Phase 1 -- From Phase 0 to Phase 1

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

Table of contents

TODO

Introduction

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

Configuration

TODO: very unstable/experimental. PLACEHOLDER.

Name Value Unit
PHASE_1_FORK_VERSION 0x00000001 Version
INITIAL_GASPRICE 10 Gwei

Fork to Phase 1

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.

Upgrading the state

After process_slots of Phase 0 finishes, but before the first Phase 1 block is processed, an irregular state change is made to upgrade to Phase 1.

def upgrade_to_phase1(pre: phase0.BeaconState) -> BeaconState:
    epoch = get_current_epoch(pre)
    post = BeaconState(
        genesis_time=pre.genesis_time,
        slot=pre.slot,
        fork=Fork(
            previous_version=pre.current_version,
            current_version=PHASE_1_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=List[Validator, VALIDATOR_REGISTRY_LIMIT](
            Validator(
                pubkey=phase0_validator.pubkey,
                withdrawal_credentials=phase0_validator.withdrawal_credentials,
                effective_balance=phase0_validator.effective_balance,
                slashed=phase0_validator.slashed,
                activation_eligibility_epoch=phase0_validator.activation_eligibility_epoch,
                activation_epoch=phase0_validator.activation_eligibility_epoch,
                exit_epoch=phase0_validator.exit_epoch,
                withdrawable_epoch=phase0_validator.withdrawable_epoch,
                next_custody_secret_to_reveal=get_custody_period_for_validator(validator_index, epoch),
                max_reveal_lateness=0,  # TODO custody refactor. Outdated? 
            ) for validator_index, phase0_validator in enumerate(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,
        # Phase 1
        shard_states=List[ShardState, MAX_SHARDS](
            ShardState(
                slot=0,
                gasprice=INITIAL_GASPRICE,
                data=Root(),
                latest_block_root=Hash(),
            ) for i in range(ACTIVE_SHARDS)
        ),
        online_countdown=Bytes[VALIDATOR_REGISTRY_LIMIT](
            ONLINE_PERIOD for i in range(len(pre.validators))            
        ),
        current_light_committee=CompactCommittee(),  # computed after state creation
        next_light_committee=CompactCommittee(),
        # Custody game
        custody_challenge_index=0,
        exposed_derived_secrets=Vector[List[ValidatorIndex, PLACEHOLDER],
                                        EARLY_DERIVED_SECRET_PENALTY_MAX_FUTURE_EPOCHS]()
    )
    post.current_light_committee = get_light_client_committee(post, post.epoch)
    post.next_light_committee = get_light_client_committee(post, post.epoch + 1)
    return post