consensus-specs/specs/_features/eip7549/validator.md

Deneb -- Honest Validator

Table of contents

• Modifications in EIP-7549
  • Block proposal
    • Constructing the BeaconBlockBody
      • Attestations
  • Attesting
    • Construct attestation
  • Attestation aggregation
    • Construct aggregate

Modifications in EIP-7549

Block proposal

Constructing the BeaconBlockBody

Attestations

The network attestation aggregates contain only the assigned committee attestations. Attestation aggregates received by the block proposer from the committee aggregators with disjoint committee_bits sets and equal AttestationData SHOULD be consolidated into a single Attestation object. The proposer should run the following function to construct an on chain final aggregate form a list of network aggregates with equal AttestationData:

def compute_on_chain_aggregate(network_aggregates: List[Attestation]) -> Attestation:
    aggregates = sorted(network_aggregates, key=lambda a: get_committee_indices(a.committee_bits)[0])

    data = aggregates[0].data
    aggregation_bits = Bitlist[MAX_VALIDATORS_PER_COMMITTEE * MAX_COMMITTEES_PER_SLOT]()
    for a in aggregates:
        for b in a.aggregation_bits:
            aggregation_bits.append(b)

    signature = bls.Aggregate([a.signature for a in aggregates])

    committee_indices = [get_committee_indices(a.committee_bits)[0] for a in aggregates]
    committee_flags = [(index in committee_indices) for index in range(0, MAX_COMMITTEES_PER_SLOT)]        
    committee_bits = Bitvector[MAX_COMMITTEES_PER_SLOT](committee_flags)

    return Attestation(aggregation_bits, data, committee_bits, signature)

Attesting

Construct attestation

• Set attestation_data.index = 0.
• Let attestation.aggregation_bits be a Bitlist[MAX_VALIDATORS_PER_COMMITTEE * MAX_COMMITTEES_PER_SLOT] of length len(committee), where the bit of the index of the validator in the committee is set to 0b1.
• Let attestation.committee_bits be a Bitvector[MAX_COMMITTEES_PER_SLOT], where the bit at the index associated with the validator's committee is set to 0b1.

Note: Calling get_attesting_indices(state, attestation) should return a list of length equal to 1, containing validator_index.

Attestation aggregation

Construct aggregate

• Set attestation_data.index = 0.
• Let aggregation_bits be a Bitlist[MAX_VALIDATORS_PER_COMMITTEE * MAX_COMMITTEES_PER_SLOT] of length len(committee), where each bit set from each individual attestation is set to 0b1.
• Set attestation.committee_bits = committee_bits, where committee_bits has the same value as in each individual attestation.