Notice: This document is a work-in-progress for researchers and implementers.
- Introduction
- Custom types
- Constants
- Preset
- Configuration
- Containers
- Helper functions
- Beacon chain state transition function
- Testing
Deneb is a consensus-layer upgrade containing a number of features. Including:
- EIP-4844: Shard Blob Transactions scale data-availability of Ethereum in a simple, forwards-compatible manner.
| Name | SSZ equivalent | Description |
|---|---|---|
VersionedHash |
Bytes32 |
[New in Deneb:EIP4844] |
BlobIndex |
uint64 |
[New in Deneb:EIP4844] |
| Name | Value |
|---|---|
DOMAIN_BLOB_SIDECAR |
DomainType('0x0B000000') |
| Name | Value |
|---|---|
BLOB_TX_TYPE |
uint8(0x03) |
VERSIONED_HASH_VERSION_KZG |
Bytes1('0x01') |
| Name | Value | Description |
|---|---|---|
MAX_BLOB_COMMITMENTS_PER_BLOCK |
uint64(2**12) (= 4096) |
[New in Deneb:EIP4844] hardfork independent fixed theoretical limit same as LIMIT_BLOBS_PER_TX (see EIP 4844) |
MAX_BLOBS_PER_BLOCK |
uint64(6) |
[New in Deneb:EIP4844] maximum number of blobs in a single block limited by MAX_BLOB_COMMITMENTS_PER_BLOCK |
Note: The blob transactions are packed into the execution payload by the EL/builder with their corresponding blobs being independently transmitted
and are limited by MAX_DATA_GAS_PER_BLOCK // DATA_GAS_PER_BLOB. However the CL limit is independently defined by MAX_BLOBS_PER_BLOCK.
Note: BeaconBlock and SignedBeaconBlock types are updated indirectly.
class BeaconBlockBody(Container):
randao_reveal: BLSSignature
eth1_data: Eth1Data # Eth1 data vote
graffiti: Bytes32 # Arbitrary data
# Operations
proposer_slashings: List[ProposerSlashing, MAX_PROPOSER_SLASHINGS]
attester_slashings: List[AttesterSlashing, MAX_ATTESTER_SLASHINGS]
attestations: List[Attestation, MAX_ATTESTATIONS]
deposits: List[Deposit, MAX_DEPOSITS]
voluntary_exits: List[SignedVoluntaryExit, MAX_VOLUNTARY_EXITS]
sync_aggregate: SyncAggregate
# Execution
execution_payload: ExecutionPayload # [Modified in Deneb:EIP4844]
bls_to_execution_changes: List[SignedBLSToExecutionChange, MAX_BLS_TO_EXECUTION_CHANGES]
blob_kzg_commitments: List[KZGCommitment, MAX_BLOB_COMMITMENTS_PER_BLOCK] # [New in Deneb:EIP4844]class ExecutionPayload(Container):
# Execution block header fields
parent_hash: Hash32
fee_recipient: ExecutionAddress # 'beneficiary' in the yellow paper
state_root: Bytes32
receipts_root: Bytes32
logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
prev_randao: Bytes32 # 'difficulty' in the yellow paper
block_number: uint64 # 'number' in the yellow paper
gas_limit: uint64
gas_used: uint64
timestamp: uint64
extra_data: ByteList[MAX_EXTRA_DATA_BYTES]
base_fee_per_gas: uint256
# Extra payload fields
block_hash: Hash32 # Hash of execution block
transactions: List[Transaction, MAX_TRANSACTIONS_PER_PAYLOAD]
withdrawals: List[Withdrawal, MAX_WITHDRAWALS_PER_PAYLOAD]
data_gas_used: uint64 # [New in Deneb:EIP4844]
excess_data_gas: uint64 # [New in Deneb:EIP4844]class ExecutionPayloadHeader(Container):
# Execution block header fields
parent_hash: Hash32
fee_recipient: ExecutionAddress
state_root: Bytes32
receipts_root: Bytes32
logs_bloom: ByteVector[BYTES_PER_LOGS_BLOOM]
prev_randao: Bytes32
block_number: uint64
gas_limit: uint64
gas_used: uint64
timestamp: uint64
extra_data: ByteList[MAX_EXTRA_DATA_BYTES]
base_fee_per_gas: uint256
# Extra payload fields
block_hash: Hash32 # Hash of execution block
transactions_root: Root
withdrawals_root: Root
data_gas_used: uint64 # [New in Deneb:EIP4844]
excess_data_gas: uint64 # [New in Deneb:EIP4844]def kzg_commitment_to_versioned_hash(kzg_commitment: KZGCommitment) -> VersionedHash:
return VERSIONED_HASH_VERSION_KZG + hash(kzg_commitment)[1:]@dataclass
class NewPayloadRequest(object):
execution_payload: ExecutionPayload
versioned_hashes: Sequence[VersionedHash]def is_valid_versioned_hashes(self: ExecutionEngine, new_payload_request: NewPayloadRequest) -> bool:
"""
Return ``True`` if and only if the version hashes computed by the blob transactions of
``new_payload_request.execution_payload`` matches ``new_payload_request.version_hashes``.
"""
...def verify_and_notify_new_payload(self: ExecutionEngine,
new_payload_request: NewPayloadRequest) -> bool:
"""
Return ``True`` if and only if ``new_payload_request`` is valid with respect to ``self.execution_state``.
"""
if not self.is_valid_block_hash(new_payload_request.execution_payload):
return False
# [New in Deneb:EIP4844]
if not self.is_valid_versioned_hashes(new_payload_request):
return False
if not self.notify_new_payload(new_payload_request.execution_payload):
return False
return Truedef process_execution_payload(state: BeaconState, body: BeaconBlockBody, execution_engine: ExecutionEngine) -> None:
payload = body.execution_payload
# Verify consistency of the parent hash with respect to the previous execution payload header
assert payload.parent_hash == state.latest_execution_payload_header.block_hash
# Verify prev_randao
assert payload.prev_randao == get_randao_mix(state, get_current_epoch(state))
# Verify timestamp
assert payload.timestamp == compute_timestamp_at_slot(state, state.slot)
# [New in Deneb:EIP4844] Verify commitments are under limit
assert len(body.blob_kzg_commitments) <= MAX_BLOBS_PER_BLOCK
# Verify the execution payload is valid
# [Modified in Deneb:EIP4844] Pass `versioned_hashes` to Execution Engine
versioned_hashes = [kzg_commitment_to_versioned_hash(commitment) for commitment in body.blob_kzg_commitments]
assert execution_engine.verify_and_notify_new_payload(
NewPayloadRequest(execution_payload=payload, versioned_hashes=versioned_hashes)
)
# Cache execution payload header
state.latest_execution_payload_header = ExecutionPayloadHeader(
parent_hash=payload.parent_hash,
fee_recipient=payload.fee_recipient,
state_root=payload.state_root,
receipts_root=payload.receipts_root,
logs_bloom=payload.logs_bloom,
prev_randao=payload.prev_randao,
block_number=payload.block_number,
gas_limit=payload.gas_limit,
gas_used=payload.gas_used,
timestamp=payload.timestamp,
extra_data=payload.extra_data,
base_fee_per_gas=payload.base_fee_per_gas,
block_hash=payload.block_hash,
transactions_root=hash_tree_root(payload.transactions),
withdrawals_root=hash_tree_root(payload.withdrawals),
data_gas_used=payload.data_gas_used, # [New in Deneb:EIP4844]
excess_data_gas=payload.excess_data_gas, # [New in Deneb:EIP4844]
)Note: The function initialize_beacon_state_from_eth1 is modified for pure Deneb testing only.
The BeaconState initialization is unchanged, except for the use of the updated deneb.BeaconBlockBody type
when initializing the first body-root.
def initialize_beacon_state_from_eth1(eth1_block_hash: Hash32,
eth1_timestamp: uint64,
deposits: Sequence[Deposit],
execution_payload_header: ExecutionPayloadHeader=ExecutionPayloadHeader()
) -> BeaconState:
fork = Fork(
previous_version=DENEB_FORK_VERSION, # [Modified in Deneb] for testing only
current_version=DENEB_FORK_VERSION, # [Modified in Deneb]
epoch=GENESIS_EPOCH,
)
state = BeaconState(
genesis_time=eth1_timestamp + GENESIS_DELAY,
fork=fork,
eth1_data=Eth1Data(block_hash=eth1_block_hash, deposit_count=uint64(len(deposits))),
latest_block_header=BeaconBlockHeader(body_root=hash_tree_root(BeaconBlockBody())),
randao_mixes=[eth1_block_hash] * EPOCHS_PER_HISTORICAL_VECTOR, # Seed RANDAO with Eth1 entropy
)
# Process deposits
leaves = list(map(lambda deposit: deposit.data, deposits))
for index, deposit in enumerate(deposits):
deposit_data_list = List[DepositData, 2**DEPOSIT_CONTRACT_TREE_DEPTH](*leaves[:index + 1])
state.eth1_data.deposit_root = hash_tree_root(deposit_data_list)
process_deposit(state, deposit)
# Process activations
for index, validator in enumerate(state.validators):
balance = state.balances[index]
validator.effective_balance = min(balance - balance % EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE)
if validator.effective_balance == MAX_EFFECTIVE_BALANCE:
validator.activation_eligibility_epoch = GENESIS_EPOCH
validator.activation_epoch = GENESIS_EPOCH
# Set genesis validators root for domain separation and chain versioning
state.genesis_validators_root = hash_tree_root(state.validators)
# Fill in sync committees
# Note: A duplicate committee is assigned for the current and next committee at genesis
state.current_sync_committee = get_next_sync_committee(state)
state.next_sync_committee = get_next_sync_committee(state)
# Initialize the execution payload header
# If empty, will initialize a chain that has not yet gone through the Merge transition
state.latest_execution_payload_header = execution_payload_header
return state