PQ Interop #4 | August 6, 2025

[will-corcoran]

Meeting Agenda

Zoom link: see Protocol calendar invite

1. DevNet-0 Spec Follow-Up
   Finalize peer discovery (static peers), block/attestation inclusion, 3SF mini modifications, and placeholder SNARK data.

2. Spec Repo Updates
   Review Poseidon2 progress and next steps for signature integration (Tamaghna/Felipe).

3. Kurtosis/Genesis Tool Support
   Update on PandaOps engagement and Genesis generator adaptations (Gajinder / Barnabas).

[unnawut]

Some 3SF-mini implementation details that we need to agree across pqinterop.

• Converting Python ref impl -> SSZ-compatible types
  • All str (block hashes) -> bytes32
  • State
    • historical_block_hashes: List[str] -> List[bytes32, MAX_HISTORICAL_BLOCK_HASHES]
    • While not in the class definition, the Python implementation implies the list can be appended with None item(s) -> use ZERO_HASH ('0'*64) instead of None
      • state.historical_block_hashes.append(None) -> state.historical_block_hashes.append(ZERO_HASH)
    • justified_slots: List[bool] -> List[bool, MAX_HISTORICAL_BLOCK_HASHES]
    • justifications: Dict[str, List[bool]] ->
      • justifications_roots: List[bytes32, MAX_HISTORICAL_BLOCK_HASHES]
      • justifications_validators: BitList[bool, MAX_HISTORICAL_BLOCK_HASHES * VALIDATOR_REGISTRY_LIMIT]
  • Block
    • parent: Optional[str] -> Remove optional, use ZERO_HASH ('0'*64) instead of None
    • votes: List[Vote] -> List[Vote, VALIDATOR_REGISTRY_LIMIT]
    • state_root: Optional[str] = None -> Remove optional, use ZERO_HASH ('0'*64) instead of None
• Presets
  • Strategy: Large enough value for devnet-0, increase over time as we get closer to production
  • MAX_HISTORICAL_BLOCK_HASHES = 262144 (2¹⁸, enough for 2^18 / (60 / 4) / 60 / 24 = 12.1 days)
  • VALIDATOR_REGISTRY_LIMIT = 4096 (2¹²)

[unnawut]

Some 3SF-mini implementation details that we need to agree across pqinterop.

• • Converting Python ref impl -> SSZ-compatible types

    • All str (block hashes) -> bytes32* State

      • historical_block_hashes: List[str] -> List[bytes32, MAX_HISTORICAL_BLOCK_HASHES]* While not in the class definition, the Python implementation implies the list can be appended with None item(s) -> use ZERO_HASH ('0'*64) instead of None

        • state.historical_block_hashes.append(None) -> state.historical_block_hashes.append(ZERO_HASH)* justified_slots: List[bool] -> List[bool, MAX_HISTORICAL_BLOCK_HASHES]* justifications: Dict[str, List[bool]] ->

        • justifications_roots: List[bytes32, MAX_HISTORICAL_BLOCK_HASHES]* justifications_validators: BitList[bool, MAX_HISTORICAL_BLOCK_HASHES * VALIDATOR_REGISTRY_LIMIT]* Block

      • parent: Optional[str] -> Remove optional, use ZERO_HASH ('0'*64) instead of None* votes: List[Vote] -> List[Vote, VALIDATOR_REGISTRY_LIMIT]* state_root: Optional[str] = None -> Remove optional, use ZERO_HASH ('0'*64) instead of None* [ ] Presets

    • Strategy: Large enough value for devnet-0, increase over time as we get closer to production* MAX_HISTORICAL_BLOCK_HASHES = 262144 (218, enough for 2^18 / (60 / 4) / 60 / 24 = 12.1 days)* VALIDATOR_REGISTRY_LIMIT = 4096 (212)

I've captured this as a PR to the spec repo itself: leanEthereum/leanSpec#5. Discussion can take place there instead