nimbus-eth2/docs/nbc_audit_2020/eth2_spec_core/fork_choice_logic.md

title	code_owner	round	category	repositories
Fork choice logic	Mamy André-Ratsimbazafy (mratsim)	Audit round 2	ETH2 Specification Core Audit	nim-beacon-chain

Fork choice backend:

• https://github.com/status-im/nim-beacon-chain/tree/unstable/beacon_chain/fork_choice

Fork choice is provided by the "attestation_pool" when "select_head" is called

• https://github.com/status-im/nim-beacon-chain/blob/unstable/beacon_chain/consensus_object_pools/attestation_pool.nim

Tests:

• https://github.com/status-im/nim-beacon-chain/tree/master/tests/fork_choice

• https://github.com/status-im/nim-beacon-chain/blob/master/tests/test_attestation_pool.nim

Specs:

• https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/fork-choice.md

• Explainer from Prysmatic: https://hackmd.io/bABJiht3Q9SyV3Ga4FT9lQ?view

Paper:

• Combining GHOST and Casper Vitalik Buterin, Diego Hernandez, Thor Kamphefner, Khiem Pham, Zhi Qiao, Danny Ryan, Juhyeok Sin, Ying Wang, Yan X Zhang https://arxiv.org/abs/2003.03052

(Short) Implementations

• https://github.com/ethereum/research/blob/master/ghost/ghost.py
• Original Proto-array (in Go): https://github.com/protolambda/lmd-ghost/blob/master/eth2/fork_choice/choices/proto_array/proto_array.go
• Proto-array incorporating Lighthouse updates: https://github.com/protolambda/eth2-py-hacks/blob/master/proto_array.py