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remove specials

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Danny Ryan 2018-12-06 19:02:23 -06:00
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specs/core/0_beacon-chain.md
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@ -17,20 +17,25 @@
- [Time parameters](#time-parameters)
- [Reward and penalty quotients](#reward-and-penalty-quotients)
- [Status codes](#status-codes)
- [Special record types](#special-record-types)
- [Max transactions](#max-transactions)
- [Validator registry delta flags](#validator-registry-delta-flags)
- [Signature domains](#signature-domains)
- [Data structures](#data-structures)
- [Deposits](#deposits)
- [`DepositParametersRecord`](#depositparametersrecord)
- [Beacon chain transactions](#beacon-chain-transactions)
- [`AttestationRecord`](#attestationrecord)
- [`AttestationData`](#attestationdata)
- [`ProposerSlashingRecord`](#proposerslashingrecord)
- [`CasperSlashingRecord`](#casperslashingrecord)
- [`SpecialAttestationData`](#specialattestationdata)
- [`DepositRecord`](#depositproofrecord)
- [`ExitRecord`](#voluntaryexitrecord)
- [Beacon chain blocks](#beacon-chain-blocks)
- [`BeaconBlockHeader`](#beaconblockheader)
- [`BeaconBlockBody`](#beaconblockbody)
- [`BeaconBlock`](#beaconblock)
- [`AttestationRecord`](#attestationrecord)
- [`AttestationData`](#attestationdata)
- [`ProposalSignedData`](#proposalsigneddata)
- [`SpecialRecord`](#specialrecord)
- [Beacon chain state](#beacon-chain-state)
- [`BeaconState`](#beaconstate)
- [`ValidatorRecord`](#validatorrecord)
@ -40,12 +45,6 @@
- [`CandidatePoWReceiptRootRecord`](#candidatepowreceiptrootrecord)
- [`PendingAttestationRecord`](#pendingattestationrecord)
- [`ForkData`](#forkdata)
- [Specials](#specials)
- [`VoluntaryExitSpecial`](#voluntaryexitspecial)
- [`CasperSlashingSpecial`](#casperslashingspecial)
- [`SpecialAttestationData`](#specialattestationdata)
- [`ProposerSlashingSpecial`](#proposerslashingspecial)
- [`DepositProofSpecial`](#depositproofspecial)
- [Ethereum 1.0 deposit contract](#ethereum-10-deposit-contract)
- [Deposit arguments](#deposit-arguments)
- [`Deposit` logs](#deposit-logs)
@ -68,20 +67,21 @@
- [`get_effective_balance`](#get_effective_balance)
- [`get_new_validator_registry_delta_chain_tip`](#get_new_validator_registry_delta_chain_tip)
- [`get_domain`](#get_domain)
- [`verify_special_attestation_data`](#verify_special_attestation_data)
- [`integer_squareroot`](#integer_squareroot)
- [On startup](#on-startup)
- [Routine for activating a validator](#routine-for-activating-a-validator)
- [Routine for exiting a validator](#routine-for-exiting-a-validator)
- [Per-slot processing](#per-slot-processing)
- [Proposer signature](#proposer-signature)
- [Attestations](#attestations)
- [RANDAO](#randao)
- [PoW receipt root](#pow-receipt-root)
- [Special objects](#special-objects)
- [`VOLUNTARY_EXIT`](#voluntary_exit)
- [`CASPER_SLASHING`](#casper_slashing)
- [`PROPOSER_SLASHING`](#proposer_slashing)
- [`DEPOSIT_PROOF`](#deposit_proof)
- [Transactions](#transactions)
- [Proposer slashings](#proposer-slashing)
- [Casper slashings](#casper-slashing)
- [Attestations](#attestations)
- [Deposits](#deposits)
- [Exits](#exits)
- [Per-epoch processing](#per-epoch-processing)
- [Helpers](#helpers)
- [Receipt roots](#receipt-roots)
@ -200,14 +200,15 @@ Unless otherwise indicated, code appearing in `this style` is to be interpreted
| `EXITED_WITHOUT_PENALTY` | `3` |
| `EXITED_WITH_PENALTY` | `4` |
### Special record types
### Max transactions
| Name | Value | Maximum count |
| Name | Value |
| - | - | :-: |
| `VOLUNTARY_EXIT` | `0` | `16` |
| `CASPER_SLASHING` | `1` | `16` |
| `PROPOSER_SLASHING` | `2` | `16` |
| `DEPOSIT_PROOF` | `3` | `16` |
| `MAX_PROPOSER_SLASHINGS` | `2**4` (= 16) |
| `MAX_CASPER_SLASHINGS` | `2**4` (= 16) |
| `MAX_ATTESTATIONS` | `2**7` (= 128) |
| `MAX_DEPOSITS` | `2**4` (= 16) |
| `MAX_EXITS` | `2**4` (= 16) |
### Validator registry delta flags
@ -244,40 +245,7 @@ Unless otherwise indicated, code appearing in `this style` is to be interpreted
}
```
### Beacon chain blocks
#### `BeaconBlockHeader`
```python
{
'slot': 'uint64',
# Skip list of ancestor beacon block hashes
# i'th item is the most recent ancestor whose slot is a multiple of 2**i for i = 0, ..., 31
'ancestor_hashes': ['hash32'],
'state_root': 'hash32',
'randao_reveal': 'hash32',
'candidate_pow_receipt_root': 'hash32',
'signature': ['uint384'],
}
```
#### `BeaconBlockBody`
```python
{
'attestations': [AttestationRecord],
'specials': [SpecialRecord],
}
```
#### `BeaconBlock`
```python
{
'header': BeaconBlockHeader,
'body': BeaconBlockBody,
}
```
### Beacon chain transactions
#### `AttestationRecord`
@ -317,6 +285,120 @@ Unless otherwise indicated, code appearing in `this style` is to be interpreted
}
```
#### `ProposerSlashingRecord`
```python
{
# Proposer index
'proposer_index': 'uint24',
# First proposal data
'proposal_data_1': ProposalSignedData,
# First proposal signature
'proposal_signature_1': '[uint384]',
# Second proposal data
'proposal_data_2': ProposalSignedData,
# Second proposal signature
'proposal_signature_2': '[uint384]',
}
```
#### `CasperSlashingRecord`
```python
{
# First vote
vote_1: SpecialAttestationData,
# Second vote
vote_2: SpecialAttestationData,
}
```
#### `SpecialAttestationData`
```python
{
# Proof-of-custody indices (0 bits)
'aggregate_signature_poc_0_indices': '[uint24]',
# Proof-of-custody indices (1 bits)
'aggregate_signature_poc_1_indices': '[uint24]',
# Attestation data
'data': AttestationData,
# Aggregate signature
'aggregate_signature': '[uint384]',
}
```
#### `DepositRecord`
```python
{
# Receipt Merkle branch
'merkle_branch': '[hash32]',
# Merkle tree index
'merkle_tree_index': 'uint64',
# Deposit data
'deposit_data': {
# Deposit parameters
'deposit_parameters': DepositParametersRecord,
# Value in Gwei
'value': 'uint64',
# Timestamp from deposit contract
'timestamp': 'uint64',
},
}
```
#### `ExitRecord`
```python
{
# Minimum slot for processing exit
'slot': 'unit64',
# Index of the exiting validator
'validator_index': 'uint64',
# Validator signature
'signature': '[uint384]',
}
```
### Beacon chain blocks
#### `BeaconBlockHeader`
```python
{
'slot': 'uint64',
# Skip list of ancestor beacon block hashes
# i'th item is the most recent ancestor whose slot is a multiple of 2**i for i = 0, ..., 31
'ancestor_hashes': ['hash32'],
'state_root': 'hash32',
'randao_reveal': 'hash32',
'candidate_pow_receipt_root': 'hash32',
'signature': ['uint384'],
}
```
#### `BeaconBlockBody`
```python
{
'attestations': [AttestationRecord],
'proposer_slashings': [ProposerSlashingRecord],
'casper_slashings': [CasperSlashingRecord],
'deposits': [DepositRecord],
'exits': [ExitRecord],
}
```
#### `BeaconBlock`
```python
{
'header': BeaconBlockHeader,
'body': BeaconBlockBody,
}
```
#### `ProposalSignedData`
```python
@ -330,17 +412,6 @@ Unless otherwise indicated, code appearing in `this style` is to be interpreted
}
```
#### `SpecialRecord`
```python
{
# Kind
'kind': 'uint64',
# Data
'data': 'bytes',
}
```
### Beacon chain state
#### `BeaconState`
@ -482,84 +553,6 @@ Unless otherwise indicated, code appearing in `this style` is to be interpreted
}
```
### Specials
#### `VoluntaryExitSpecial`
```python
{
# Minimum slot for processing exit
'slot': 'unit64',
# Index of the exiting validator
'validator_index': 'uint64',
# Validator signature
'signature': '[uint384]',
}
```
#### `CasperSlashingSpecial`
```python
{
# First vote
vote_1: SpecialAttestationData,
# Second vote
vote_2: SpecialAttestationData,
}
```
#### `SpecialAttestationData`
```python
{
# Proof-of-custody indices (0 bits)
'aggregate_signature_poc_0_indices': '[uint24]',
# Proof-of-custody indices (1 bits)
'aggregate_signature_poc_1_indices': '[uint24]',
# Attestation data
'data': AttestationData,
# Aggregate signature
'aggregate_signature': '[uint384]',
}
```
#### `ProposerSlashingSpecial`
```python
{
# Proposer index
'proposer_index': 'uint24',
# First proposal data
'proposal_data_1': ProposalSignedData,
# First proposal signature
'proposal_signature_1': '[uint384]',
# Second proposal data
'proposal_data_2': ProposalSignedData,
# Second proposal signature
'proposal_signature_2': '[uint384]',
}
```
#### `DepositProofSpecial`
```python
{
# Receipt Merkle branch
'merkle_branch': '[hash32]',
# Merkle tree index
'merkle_tree_index': 'uint64',
# Deposit data
'deposit_data': {
# Deposit parameters
'deposit_parameters': DepositParametersRecord,
# Value in Gwei
'value': 'uint64',
# Timestamp from deposit contract
'timestamp': 'uint64',
},
}
```
## Ethereum 1.0 deposit contract
The initial deployment phases of Ethereum 2.0 are implemented without consensus changes to Ethereum 1.0. A deposit contract at address `DEPOSIT_CONTRACT_ADDRESS` is added to Ethereum 1.0 for deposits of ETH to the beacon chain. Validator balances will be withdrawable to the shards when the EVM2.0 is deployed and the shards have state.
@ -960,6 +953,15 @@ def get_domain(fork_data: ForkData,
) * 2**32 + domain_type
```
#### `verify_special_attestation_data`
```python
def verify_special_attestation_data(state: State, obj: SpecialAttestationData) -> bool:
pubs = [aggregate_pubkey([state.validators[i].pubkey for i in obj.aggregate_signature_poc_0_indices]),
aggregate_pubkey([state.validators[i].pubkey for i in obj.aggregate_signature_poc_1_indices])]
return BLSMultiVerify(pubkeys=pubs, msgs=[SSZTreeHash(obj)+bytes1(0), SSZTreeHash(obj)+bytes1(1), sig=aggregate_signature)
```
#### `integer_squareroot`
```python
@ -981,14 +983,21 @@ A valid block with slot `INITIAL_SLOT_NUMBER` (a "genesis block") has the follow
```python
{
'slot': INITIAL_SLOT_NUMBER,
'randao_reveal': ZERO_HASH,
'candidate_pow_receipt_root': ZERO_HASH,
'ancestor_hashes': [ZERO_HASH for i in range(32)],
'state_root': STARTUP_STATE_ROOT,
'attestations': [],
'specials': [],
'proposer_signature': [0, 0],
'header': BeaconBlockHeader(
slot=INITIAL_SLOT_NUMBER,
ancestor_hashes=[ZERO_HASH for i in range(32)],
state_root=STARTUP_STATE_ROOT,
randao_reveal=ZERO_HASH,
candidate_pow_receipt_root=ZERO_HASH,
proposer_signature=[0, 0]
),
'body': BeaconBlockBody(
proposer_slashings=[],
casper_slashings=[],
attestations=[],
deposits=[],
exits=[]
),
}
```
@ -1236,9 +1245,54 @@ If there is no block from the proposer at state.slot:
* Let `proposal_hash = hash(ProposalSignedData(state.slot, BEACON_CHAIN_SHARD_NUMBER, block_hash_without_sig))`.
* Verify that `BLSVerify(pubkey=state.validator_registry[get_beacon_proposer_index(state, state.slot)].pubkey, data=proposal_hash, sig=block.header.signature, domain=get_domain(state.fork_data, state.slot, DOMAIN_PROPOSAL))`.
### Attestations
### RANDAO
* Verify that `len(block.body.attestations) <= MAX_ATTESTATIONS_PER_BLOCK`.
* Let `repeat_hash(x, n) = x if n == 0 else repeat_hash(hash(x), n-1)`.
* Let `proposer = state.validator_registry[get_beacon_proposer_index(state, state.slot)]`.
* Verify that `repeat_hash(block.header.randao_reveal, proposer.randao_skips + 1) == proposer.randao_commitment`.
* Set `state.randao_mix = xor(state.randao_mix, block.header.randao_reveal)`.
* Set `proposer.randao_commitment = block.header.randao_reveal`.
* Set `proposer.randao_skips = 0`.
### PoW receipt root
* If `block.header.candidate_pow_receipt_root` is `x.candidate_pow_receipt_root` for some `x` in `state.candidate_pow_receipt_roots`, set `x.votes += 1`.
* Otherwise, append to `state.candidate_pow_receipt_roots` a new `CandidatePoWReceiptRootRecord(candidate_pow_receipt_root=block.header.candidate_pow_receipt_root, votes=1)`.
### Transactions
#### Proposer slashings
Verify that `len(block.body.proposer_slashings) <= MAX_PROPOSER_SLASHINGS`.
For each `proposer_slashing` in `block.body.proposer_slashings`:
* Let `proposer = state.validator_registry[proposer_slashing.proposer_index]`
* Verify that `BLSVerify(pubkey=proposer.pubkey, msg=hash(proposer_slashing.proposal_data_1), sig=proposer_slashing.proposal_signature_1, domain=get_domain(state.fork_data, proposer_slashing.proposal_data_1.slot, DOMAIN_PROPOSAL))`.
* Verify that `BLSVerify(pubkey=proposer.pubkey, msg=hash(proposer_slashing.proposal_data_2), sig=proposer_slashing.proposal_signature_2, domain=get_domain(state.fork_data, proposer_slashing.proposal_data_2.slot, DOMAIN_PROPOSAL))`.
* Verify that `proposer_slashing.proposal_data_1 != proposer_slashing.proposal_data_2`.
* Verify that `proposer_slashing.proposal_data_1.slot == proposer_slashing.proposal_data_2.slot`.
* Verify that `proposer.status != EXITED_WITH_PENALTY`.
* Run `exit_validator(proposer_slashing.proposer_index, state, penalize=True, current_slot=state.slot)`.
#### Casper slashings
Verify that `len(block.body.casper_slashings) <= MAX_CASPER_SLASHINGS`.
For each `casper_slashing` in `block.body.casper_slashings`:
* Verify that `verify_special_attestation_data(casper_slashing.vote_1)`.
* Verify that `verify_special_attestation_data(casper_slashing.vote_2)`.
* Verify that `casper_slashing.vote_1.data != casper_slashing.vote_2.data`.
* Let `indices(vote) = vote.aggregate_signature_poc_0_indices + vote.aggregate_signature_poc_1_indices`.
* Let `intersection = [x for x in indices(casper_slashing.vote_1) if x in indices(casper_slashing.vote_2)]`.
* Verify that `len(intersection) >= 1`.
* Verify that `casper_slashing.vote_1.data.justified_slot + 1 < casper_slashing.vote_2.data.justified_slot + 1 == casper_slashing.vote_2.data.slot < casper_slashing.vote_1.data.slot` or `casper_slashing.vote_1.data.slot == casper_slashing.vote_2.data.slot`.
* For each [validator](#dfn-validator) index `i` in `intersection`, if `state.validator_registry[i].status` does not equal `EXITED_WITH_PENALTY`, then run `exit_validator(i, state, penalize=True, current_slot=state.slot)`
#### Attestations
Verify that `len(block.body.attestations) <= MAX_ATTESTATIONS`.
For each `attestation` in `block.body.attestations`:
@ -1254,75 +1308,14 @@ For each `attestation` in `block.body.attestations`:
* [TO BE REMOVED IN PHASE 1] Verify that `shard_block_hash == ZERO_HASH`.
* Append `PendingAttestationRecord(data=attestation.data, participation_bitfield=attestation.participation_bitfield, custody_bitfield=attestation.custody_bitfield, slot_included=state.slot)` to `state.latest_attestations`.
### RANDAO
#### Deposits
* Let `repeat_hash(x, n) = x if n == 0 else repeat_hash(hash(x), n-1)`.
* Let `proposer = state.validator_registry[get_beacon_proposer_index(state, state.slot)]`.
* Verify that `repeat_hash(block.header.randao_reveal, proposer.randao_skips + 1) == proposer.randao_commitment`.
* Set `state.randao_mix = xor(state.randao_mix, block.header.randao_reveal)`.
* Set `proposer.randao_commitment = block.header.randao_reveal`.
* Set `proposer.randao_skips = 0`.
Verify that `len(block.body.deposits) <= MAX_DEPOSITS`.
### PoW receipt root
For each `deposit` in `block.body.deposits`:
* If `block.header.candidate_pow_receipt_root` is `x.candidate_pow_receipt_root` for some `x` in `state.candidate_pow_receipt_roots`, set `x.votes += 1`.
* Otherwise, append to `state.candidate_pow_receipt_roots` a new `CandidatePoWReceiptRootRecord(candidate_pow_receipt_root=block.header.candidate_pow_receipt_root, votes=1)`.
### Special objects
* Verify that the quantity of each type of object in `block.body.specials` is less than or equal to its maximum (see table at the top).
* Verify that objects are sorted in order of `kind`. That is, `block.body.specials[i+1].kind >= block.body.specials[i].kind` for `0 <= i < len(block.body.specials-1)`.
For each `special` in `block.body.specials`:
* Verify that `special.kind` is a valid value.
* Verify that `special.data` deserializes according to the format for the given `kind` (see format definitions in "Data structures" above).
* Process `special.data` as specified below for each kind.
#### `VOLUNTARY_EXIT`
* Let `validator = state.validator_registry[validator_index]`.
* Verify that `BLSVerify(pubkey=validator.pubkey, msg=ZERO_HASH, sig=signature, domain=get_domain(state.fork_data, slot, DOMAIN_EXIT))`.
* Verify that `validator.status == ACTIVE`.
* Verify that `state.slot >= slot`.
* Verify that `state.slot >= validator.latest_status_change_slot + SHARD_PERSISTENT_COMMITTEE_CHANGE_PERIOD`.
* Run `exit_validator(validator_index, state, penalize=False, current_slot=state.slot)`.
#### `CASPER_SLASHING`
Let `verify_special_attestation_data` be the following helper:
```python
def verify_special_attestation_data(state: State, obj: SpecialAttestationData) -> bool:
pubs = [aggregate_pubkey([state.validators[i].pubkey for i in obj.aggregate_signature_poc_0_indices]),
aggregate_pubkey([state.validators[i].pubkey for i in obj.aggregate_signature_poc_1_indices])]
return BLSMultiVerify(pubkeys=pubs, msgs=[SSZTreeHash(obj)+bytes1(0), SSZTreeHash(obj)+bytes1(1), sig=aggregate_signature)
```
* Verify that `verify_special_attestation_data(vote_1)`.
* Verify that `verify_special_attestation_data(vote_2)`.
* Verify that `vote_1.data != vote_2.data`.
* Let `indices(vote) = vote.aggregate_signature_poc_0_indices + vote.aggregate_signature_poc_1_indices`.
* Let `intersection = [x for x in indices(vote_1) if x in indices(vote_2)]`.
* Verify that `len(intersection) >= 1`.
* Verify that `vote_1.data.justified_slot + 1 < vote_2.data.justified_slot + 1 == vote_2.data.slot < vote_1.data.slot` or `vote_1.data.slot == vote_2.data.slot`.
For each [validator](#dfn-validator) index `i` in `intersection`, if `state.validator_registry[i].status` does not equal `EXITED_WITH_PENALTY`, then run `exit_validator(i, state, penalize=True, current_slot=state.slot)`
#### `PROPOSER_SLASHING`
* Verify that `BLSVerify(pubkey=state.validator_registry[proposer_index].pubkey, msg=hash(proposal_data_1), sig=proposal_signature_1, domain=get_domain(state.fork_data, proposal_data_1.slot, DOMAIN_PROPOSAL))`.
* Verify that `BLSVerify(pubkey=state.validator_registry[proposer_index].pubkey, msg=hash(proposal_data_2), sig=proposal_signature_2, domain=get_domain(state.fork_data, proposal_data_2.slot, DOMAIN_PROPOSAL))`.
* Verify that `proposal_data_1 != proposal_data_2`.
* Verify that `proposal_data_1.slot == proposal_data_2.slot`.
* Verify that `state.validator_registry[proposer_index].status != EXITED_WITH_PENALTY`.
* Run `exit_validator(proposer_index, state, penalize=True, current_slot=state.slot)`.
#### `DEPOSIT_PROOF`
Let `serialized_deposit_data` be the serialized form of `deposit_data. It should be the `DepositParametersRecord` followed by 8 bytes for `deposit_data.value` and 8 bytes for `deposit_data.timestamp`. That is, it should match `deposit_data` in the [Ethereum 1.0 deposit contract](#ethereum-10-chain-deposit-contract) of which the hash was placed into the Merkle tree.
Use the following procedure to verify the `merkle_branch`, setting `leaf=serialized_deposit_data`, `depth=DEPOSIT_CONTRACT_TREE_DEPTH` and `root=state.processed_pow_receipt_root`:
* Let `serialized_deposit_data` be the serialized form of `deposit.deposit_data`. It should be the `DepositParametersRecord` followed by 8 bytes for `deposit_data.value` and 8 bytes for `deposit_data.timestamp`. That is, it should match `deposit_data` in the [Ethereum 1.0 deposit contract](#ethereum-10-chain-deposit-contract) of which the hash was placed into the Merkle tree.
* Use the following procedure to verify `deposit.merkle_branch`, setting `leaf=serialized_deposit_data`, `depth=DEPOSIT_CONTRACT_TREE_DEPTH` and `root=state.processed_pow_receipt_root`:
```python
def verify_merkle_branch(leaf: Hash32, branch: [Hash32], depth: int, index: int, root: Hash32) -> bool:
@ -1335,22 +1328,35 @@ def verify_merkle_branch(leaf: Hash32, branch: [Hash32], depth: int, index: int,
return value == root
```
* Verify that `state.slot - (deposit_data.timestamp - state.genesis_time) // SLOT_DURATION < ZERO_BALANCE_VALIDATOR_TTL`.
* Verify that `state.slot - (deposit.deposit_data.timestamp - state.genesis_time) // SLOT_DURATION < ZERO_BALANCE_VALIDATOR_TTL`.
* Run the following:
```python
process_deposit(
state=state,
pubkey=deposit_data.deposit_parameters.pubkey,
deposit=deposit_data.value,
proof_of_possession=deposit_data.deposit_parameters.proof_of_possession,
withdrawal_credentials=deposit_data.deposit_parameters.withdrawal_credentials,
randao_commitment=deposit_data.deposit_parameters.randao_commitment,
pubkey=deposit.deposit_data.deposit_parameters.pubkey,
deposit=deposit.deposit_data.value,
proof_of_possession=deposit.deposit_data.deposit_parameters.proof_of_possession,
withdrawal_credentials=deposit.deposit_data.deposit_parameters.withdrawal_credentials,
randao_commitment=deposit.deposit_data.deposit_parameters.randao_commitment,
status=PENDING_ACTIVATION,
current_slot=state.slot
)
```
#### Exits
Verify that `len(block.body.exits) <= MAX_EXITS`.
For each `exit` in `block.body.exits`:
* Let `validator = state.validator_registry[exit.validator_index]`.
* Verify that `BLSVerify(pubkey=validator.pubkey, msg=ZERO_HASH, sig=exit.signature, domain=get_domain(state.fork_data, exit.slot, DOMAIN_EXIT))`.
* Verify that `validator.status == ACTIVE`.
* Verify that `state.slot >= exit.slot`.
* Verify that `state.slot >= validator.latest_status_change_slot + SHARD_PERSISTENT_COMMITTEE_CHANGE_PERIOD`.
* Run `exit_validator(validator_index, state, penalize=False, current_slot=state.slot)`.
## Per-epoch processing
The steps below happen when `state.slot % EPOCH_LENGTH == 0`.