From 2186c45f84b09fcd0733e81c0468b5d5feca9822 Mon Sep 17 00:00:00 2001 From: protolambda Date: Fri, 25 Oct 2019 13:22:59 +0200 Subject: [PATCH] implement (unpolished) solution for #1446, based on suggested use of eth1 hash --- specs/core/0_beacon-chain.md | 3 +++ test_libs/pyspec/eth2spec/test/helpers/genesis.py | 8 +++++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md index 9a680dc7d..4a62342ed 100644 --- a/specs/core/0_beacon-chain.md +++ b/specs/core/0_beacon-chain.md @@ -1113,6 +1113,9 @@ def initialize_beacon_state_from_eth1(eth1_block_hash: Hash, eth1_data=Eth1Data(block_hash=eth1_block_hash, deposit_count=len(deposits)), latest_block_header=BeaconBlockHeader(body_root=hash_tree_root(BeaconBlockBody())), ) + # Set the initial RANDAO mixes to hashes seeded by the Eth1 hash, to limit deposit ordering committee bias. + for i in range(MIN_SEED_LOOKAHEAD + 1): + state.randao_mixes[EPOCHS_PER_HISTORICAL_VECTOR - i - 1] = hash(eth1_block_hash + int_to_bytes(i, 8)) # Process deposits leaves = list(map(lambda deposit: deposit.data, deposits)) diff --git a/test_libs/pyspec/eth2spec/test/helpers/genesis.py b/test_libs/pyspec/eth2spec/test/helpers/genesis.py index 9e3c77b7b..6a9b8f9f1 100644 --- a/test_libs/pyspec/eth2spec/test/helpers/genesis.py +++ b/test_libs/pyspec/eth2spec/test/helpers/genesis.py @@ -19,17 +19,23 @@ def build_mock_validator(spec, i: int, balance: int): def create_genesis_state(spec, num_validators): deposit_root = b'\x42' * 32 + eth1_block_hash = b'\xda' * 32 state = spec.BeaconState( genesis_time=0, eth1_deposit_index=num_validators, eth1_data=spec.Eth1Data( deposit_root=deposit_root, deposit_count=num_validators, - block_hash=spec.Hash(), + block_hash=eth1_block_hash, ), latest_block_header=spec.BeaconBlockHeader(body_root=spec.hash_tree_root(spec.BeaconBlockBody())), ) + # Set the initial RANDAO mixes to hashes seeded by the Eth1 hash, to limit deposit ordering committee bias. + for i in range(spec.MIN_SEED_LOOKAHEAD + 1): + state.randao_mixes[spec.EPOCHS_PER_HISTORICAL_VECTOR - i - 1] = \ + spec.hash(eth1_block_hash + spec.int_to_bytes(i, 8)) + # We "hack" in the initial validators, # as it is much faster than creating and processing genesis deposits for every single test case. state.balances = [spec.MAX_EFFECTIVE_BALANCE] * num_validators