From f77b9e241435e7b67a81cf5feabe595265d5f4c8 Mon Sep 17 00:00:00 2001 From: vbuterin Date: Fri, 22 Feb 2019 00:21:56 -0600 Subject: [PATCH] Changed name to crosslink data commitment --- specs/core/0_beacon-chain.md | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md index 1d3ae80ef..fcca0d47e 100644 --- a/specs/core/0_beacon-chain.md +++ b/specs/core/0_beacon-chain.md @@ -363,7 +363,7 @@ The following data structures are defined as [SimpleSerialize (SSZ)](https://git # Root of the ancestor at the epoch boundary 'epoch_boundary_root': 'bytes32', # Data from the shard since the last attestation - 'shard_data_commitment': 'bytes32', + 'crosslink_data_root': 'bytes32', # Last crosslink 'latest_crosslink': Crosslink, # Last justified epoch in the beacon state @@ -584,8 +584,8 @@ The following data structures are defined as [SimpleSerialize (SSZ)](https://git { # Epoch number 'epoch': 'uint64', - # Shard block root - 'shard_data_commitment': 'bytes32', + # Shard data since the previous crosslink + 'crosslink_data_root': 'bytes32', } ``` @@ -1475,7 +1475,7 @@ def get_genesis_beacon_state(genesis_validator_deposits: List[Deposit], finalized_epoch=GENESIS_EPOCH, # Recent state - latest_crosslinks=[Crosslink(epoch=GENESIS_EPOCH, shard_data_commitment=ZERO_HASH) for _ in range(SHARD_COUNT)], + latest_crosslinks=[Crosslink(epoch=GENESIS_EPOCH, crosslink_data_root=ZERO_HASH) for _ in range(SHARD_COUNT)], latest_block_roots=[ZERO_HASH for _ in range(LATEST_BLOCK_ROOTS_LENGTH)], latest_active_index_roots=[ZERO_HASH for _ in range(LATEST_ACTIVE_INDEX_ROOTS_LENGTH)], latest_slashed_balances=[0 for _ in range(LATEST_SLASHED_EXIT_LENGTH)], @@ -1674,7 +1674,7 @@ For each `attestation` in `block.body.attestations`: * Verify that `attestation.data.slot <= state.slot - MIN_ATTESTATION_INCLUSION_DELAY < attestation.data.slot + SLOTS_PER_EPOCH`. * Verify that `attestation.data.justified_epoch` is equal to `state.justified_epoch if slot_to_epoch(attestation.data.slot + 1) >= get_current_epoch(state) else state.previous_justified_epoch`. * Verify that `attestation.data.justified_block_root` is equal to `get_block_root(state, get_epoch_start_slot(attestation.data.justified_epoch))`. -* Verify that either (i) `state.latest_crosslinks[attestation.data.shard] == attestation.data.latest_crosslink` or (ii) `state.latest_crosslinks[attestation.data.shard] == Crosslink(shard_data_commitment=attestation.data.shard_data_commitment, epoch=slot_to_epoch(attestation.data.slot))`. +* Verify that either (i) `state.latest_crosslinks[attestation.data.shard] == attestation.data.latest_crosslink` or (ii) `state.latest_crosslinks[attestation.data.shard] == Crosslink(crosslink_data_root=attestation.data.crosslink_data_root, epoch=slot_to_epoch(attestation.data.slot))`. * Verify bitfields and aggregate signature: ```python @@ -1707,7 +1707,7 @@ For each `attestation` in `block.body.attestations`: ) ``` -* [TO BE REMOVED IN PHASE 1] Verify that `attestation.data.shard_data_commitment == ZERO_HASH`. +* [TO BE REMOVED IN PHASE 1] Verify that `attestation.data.crosslink_data_root == ZERO_HASH`. * Append `PendingAttestation(data=attestation.data, aggregation_bitfield=attestation.aggregation_bitfield, custody_bitfield=attestation.custody_bitfield, inclusion_slot=state.slot)` to `state.latest_attestations`. ##### Deposits @@ -1815,10 +1815,10 @@ The steps below happen when `(state.slot + 1) % SLOTS_PER_EPOCH == 0`. For every `slot in range(get_epoch_start_slot(previous_epoch), get_epoch_start_slot(next_epoch))`, let `crosslink_committees_at_slot = get_crosslink_committees_at_slot(state, slot)`. For every `(crosslink_committee, shard)` in `crosslink_committees_at_slot`, compute: -* Let `shard_data_commitment` be `state.latest_crosslinks[shard].shard_data_commitment` -* Let `attesting_validator_indices(crosslink_committee, shard_data_commitment)` be the union of the [validator](#dfn-validator) index sets given by `[get_attestation_participants(state, a.data, a.aggregation_bitfield) for a in current_epoch_attestations + previous_epoch_attestations if a.data.shard == shard and a.data.shard_data_commitment == shard_data_commitment]`. -* Let `winning_data_commitment(crosslink_committee)` be equal to the value of `shard_data_commitment` such that `get_total_balance(state, attesting_validator_indices(crosslink_committee, shard_data_commitment))` is maximized (ties broken by favoring lower `shard_data_commitment` values). -* Let `attesting_validators(crosslink_committee)` be equal to `attesting_validator_indices(crosslink_committee, winning_data_commitment(crosslink_committee))` for convenience. +* Let `crosslink_data_root` be `state.latest_crosslinks[shard].crosslink_data_root` +* Let `attesting_validator_indices(crosslink_committee, crosslink_data_root)` be the union of the [validator](#dfn-validator) index sets given by `[get_attestation_participants(state, a.data, a.aggregation_bitfield) for a in current_epoch_attestations + previous_epoch_attestations if a.data.shard == shard and a.data.crosslink_data_root == crosslink_data_root]`. +* Let `winning_root(crosslink_committee)` be equal to the value of `crosslink_data_root` such that `get_total_balance(state, attesting_validator_indices(crosslink_committee, crosslink_data_root))` is maximized (ties broken by favoring lower `crosslink_data_root` values). +* Let `attesting_validators(crosslink_committee)` be equal to `attesting_validator_indices(crosslink_committee, winning_root(crosslink_committee))` for convenience. * Let `total_attesting_balance(crosslink_committee) = get_total_balance(state, attesting_validators(crosslink_committee))`. Define the following helpers to process attestation inclusion rewards and inclusion distance reward/penalty. For every attestation `a` in `previous_epoch_attestations`: @@ -1858,7 +1858,7 @@ Finally, update the following: For every `slot in range(get_epoch_start_slot(previous_epoch), get_epoch_start_slot(next_epoch))`, let `crosslink_committees_at_slot = get_crosslink_committees_at_slot(state, slot)`. For every `(crosslink_committee, shard)` in `crosslink_committees_at_slot`, compute: -* Set `state.latest_crosslinks[shard] = Crosslink(epoch=slot_to_epoch(slot), shard_data_commitment=winning_data_commitment(crosslink_committee))` if `3 * total_attesting_balance(crosslink_committee) >= 2 * get_total_balance(crosslink_committee)`. +* Set `state.latest_crosslinks[shard] = Crosslink(epoch=slot_to_epoch(slot), crosslink_data_root=winning_root(crosslink_committee))` if `3 * total_attesting_balance(crosslink_committee) >= 2 * get_total_balance(crosslink_committee)`. #### Rewards and penalties