Remove `deposit` and `eth1data` fields

Abstract

This EIP removes the legacy deposit and Eth1 data fields from the BeaconBlockBody and BeaconState structures after EIP-6110 has been fully finalized. These fields become obsolete once all validators have transitioned to the new in-protocol deposit processing mechanism introduced in EIP-6110.

Motivation

EIP-6110 introduced in-protocol deposit processing by moving validator deposits to the execution layer as part of the EIP-7685 request framework. This change eliminated the need for the consensus layer's proposer voting mechanism for deposits. However, during the transition period, both the legacy deposit mechanism (using deposits and eth1_data fields) and the new mechanism coexist to ensure smooth migration.

Once EIP-6110 has been fully finalized and the transition period is complete (when state.eth1_deposit_index == state.deposit_requests_start_index), the legacy deposit fields become permanently unused and can be safely removed. The Fulu fork removed legacy deposit processing and requires body.deposits to be empty. This EIP removes the remaining deposits and eth1_data block body fields, the Eth1 data voting machinery, and the unused BeaconState fields, providing several benefits:

• Simplified validation: Removes deprecated validation logic and code paths
• Improved maintainability: Eliminates technical debt from the transition period

Specification

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 and RFC 8174.

Consensus Layer

Activation Conditions

This EIP SHALL only be activated when both of the following conditions are met:

1. EIP-6110 has been fully finalized: state.eth1_deposit_index == state.deposit_requests_start_index
2. Glamsterdam (EIP-7773) is in effect

BeaconBlockBody Modifications

The BeaconBlockBody container is modified to remove the following fields:

Removed fields:

• eth1_data: Eth1Data
• deposits: ProgressiveList[Deposit]

The removal is expressed by setting the corresponding active_fields bits of the ProgressiveContainer to 0, as specified in EIP-7688.

The updated BeaconBlockBody structure becomes:

class BeaconBlockBody(
    ProgressiveContainer(active_fields=[1] + [0] + [1] * 4 + [0] + [1] * 6)
):
    randao_reveal: BLSSignature
    # Removed `eth1_data`
    graffiti: Bytes32
    proposer_slashings: ProgressiveList[ProposerSlashing]
    attester_slashings: ProgressiveList[AttesterSlashing]
    attestations: ProgressiveList[Attestation]
    # Removed `deposits`
    voluntary_exits: ProgressiveList[SignedVoluntaryExit]
    sync_aggregate: SyncAggregate
    bls_to_execution_changes: ProgressiveList[SignedBLSToExecutionChange]
    signed_execution_payload_bid: SignedExecutionPayloadBid
    payload_attestations: ProgressiveList[PayloadAttestation]
    parent_execution_requests: ExecutionRequests

Validation Changes

Block processing modifications:

1. Remove the process_eth1_data() call from process_block
2. Remove the assert len(body.deposits) == 0 check from process_operations

Epoch processing modifications:

1. Remove the process_eth1_data_reset() call from process_epoch

Honest validator modifications:

1. Remove the Eth1 data polling and get_eth1_vote machinery; proposers no longer include an eth1_data vote in their blocks

BeaconState Modifications

The BeaconState container is modified to remove the following fields:

Removed fields:

• eth1_data: Eth1Data
• eth1_data_votes: List[Eth1Data, EPOCHS_PER_ETH1_VOTING_PERIOD * SLOTS_PER_EPOCH]
• eth1_deposit_index: uint64
• deposit_requests_start_index: uint64

The removal is expressed by setting the corresponding active_fields bits of the ProgressiveContainer to 0.

The updated BeaconState structure becomes:

class BeaconState(
    ProgressiveContainer(active_fields=[1] * 8 + [0] * 3 + [1] * 17 + [0] + [1] * 17)
):
    genesis_time: uint64
    genesis_validators_root: Root
    slot: Slot
    fork: Fork
    latest_block_header: BeaconBlockHeader
    block_roots: Vector[Root, SLOTS_PER_HISTORICAL_ROOT]
    state_roots: Vector[Root, SLOTS_PER_HISTORICAL_ROOT]
    historical_roots: List[Root, HISTORICAL_ROOTS_LIMIT]
    # Removed `eth1_data`
    # Removed `eth1_data_votes`
    # Removed `eth1_deposit_index`
    validators: ProgressiveList[Validator]
    balances: ProgressiveList[Gwei]
    randao_mixes: Vector[Bytes32, EPOCHS_PER_HISTORICAL_VECTOR]
    slashings: Vector[Gwei, EPOCHS_PER_SLASHINGS_VECTOR]
    previous_epoch_participation: ProgressiveList[ParticipationFlags]
    current_epoch_participation: ProgressiveList[ParticipationFlags]
    justification_bits: Bitvector[JUSTIFICATION_BITS_LENGTH]
    previous_justified_checkpoint: Checkpoint
    current_justified_checkpoint: Checkpoint
    finalized_checkpoint: Checkpoint
    inactivity_scores: ProgressiveList[uint64]
    current_sync_committee: SyncCommittee
    next_sync_committee: SyncCommittee
    latest_block_hash: Hash32
    next_withdrawal_index: WithdrawalIndex
    next_withdrawal_validator_index: ValidatorIndex
    historical_summaries: List[HistoricalSummary, HISTORICAL_ROOTS_LIMIT]
    # Removed `deposit_requests_start_index`
    deposit_balance_to_consume: Gwei
    exit_balance_to_consume: Gwei
    earliest_exit_epoch: Epoch
    consolidation_balance_to_consume: Gwei
    earliest_consolidation_epoch: Epoch
    pending_deposits: ProgressiveList[PendingDeposit]
    pending_partial_withdrawals: ProgressiveList[PendingPartialWithdrawal]
    pending_consolidations: ProgressiveList[PendingConsolidation]
    proposer_lookahead: Vector[ValidatorIndex, (MIN_SEED_LOOKAHEAD + 1) * SLOTS_PER_EPOCH]
    builders: ProgressiveList[Builder]
    next_withdrawal_builder_index: BuilderIndex
    execution_payload_availability: Bitvector[SLOTS_PER_HISTORICAL_ROOT]
    builder_pending_payments: Vector[BuilderPendingPayment, 2 * SLOTS_PER_EPOCH]
    builder_pending_withdrawals: ProgressiveList[BuilderPendingWithdrawal]
    latest_execution_payload_bid: ExecutionPayloadBid
    payload_expected_withdrawals: ProgressiveList[Withdrawal]
    ptc_window: Vector[Vector[ValidatorIndex, PTC_SIZE], (2 + MIN_SEED_LOOKAHEAD) * SLOTS_PER_EPOCH]

Rationale

Timing of Removal

The fields are removed after EIP-6110 finalization to ensure:

• All pending deposits from the legacy system have been processed
• No validator can be affected by the removal
• The transition is complete and irreversible
• State consistency is maintained across all honest nodes

Backwards Compatibility

Because BeaconBlockBody and BeaconState are ProgressiveContainers, the proposed changes do not affect the generalized indices of remaining fields. Merkle-proof verifiers of unrelated fields continue to work. Historical blocks and states retain their original schemas and remain verifiable.

Security Considerations

The removal of legacy fields poses minimal security risk because:

• The fields are already unused after EIP-6110 finalization
• All deposits are processed through the new EIP-6110 mechanism

Copyright

Copyright and related rights waived via CC0.