AQEAB: attestation aggregation in blocks

This is a sub-milestone of %(2024Q4) Attestation Quorum Expansion to All Bakers

People

@ACoquereau, @4dam

Motivation

Reducing the attestations' footprint in blocks, lowering storage and network consumption.

Plan

• Under feature flag, bakers now aggregate BLS attestations into a single newly introduced Attestations_aggregate operation.

Work breakdown

• Protocol feature

  • Attestation slots are no longer signed.

    • !16607 (merged) - Proto: add Operation.bls_mode_unsigned_encoding
    • !16655 (merged) - Client: register operation.bls_mode_unsigned encoding
    • !16306 (merged) - Proto: operations signature check has access to the context
    • !15436 (merged) - Proto: attestation slots are no longer signed (under feature flag)
    • !15879 (merged) - Proto: double attesting with different slots is no longer slashed (under feature flag)
    • !15888 (merged) - Accuser: double attesting with different slots is no longer denunced (under feature flag)
    • !16793 (merged) - Proto: mempool check for consensus vote's minimal slots

  • New aggregated_attestation operation for Tz4 addresses

    • New operation under feature flag
      • !15283 (merged) - Proto: add aggregate_attestation feature flag
      • !16169 (merged) - Proto: minor encodings refactoring
      • !16167 (merged) - Proto: minor refactor for conflicts handling in double-attesting validation
      • !16358 (merged) - Proto: minor refactoring for double (pre)attesting application
      • !15244 (merged) - Proto: add attestation_aggregate consensus operation
      • !16638 (merged) - Accuser: refactor aggregate cases handling
    • Validation in blocks (application and construction)
      • !17139 (merged) - Proto: implement attestations aggregate validation
      • !17332 (merged) - Proto: a valid block include at most one Attestations_aggregate
      • !17447 (merged) - Proto: unaggregated eligible attestations are invalid in blocks
      • !17756 (merged) - Proto: check for empty aggregate comittee
    • Application in blocks
      • !17149 (merged) - Proto: implement attestations aggregate application
      • !17150 (merged) - Proto: add basic unit testing for attestations aggregate
      • !17169 (merged) - Proto: add more basic unit testing for attestations aggregate
      • !17930 (merged) - Proto/apply: fix aggregate metadata committee ordering
    • #7827 - Follow-up testing for attestations aggregate

  • Baker

    • !17208 (merged) - Baker: aggregate tz4 attestations
    • !17313 (merged) - Tezt: add baker tests for aggregation
    • !17618 (merged) - Baker: fix branch filtering
    • !17578 (merged) - Tezt: add a test for aggregations in reproposals
    • !17624 (merged) - Baker: improve voting power monitoring
    • !17917 (merged) - Baker: fix attestations with DAL aggregation when repropsing
    • #7868 - Proto: mempool filters consensus operations branch

  • Preattestations aggregation

    • !17457 (merged) - Proto: remove preattestations slots from bls_mode encoding
    • !17645 (merged) - Tezt: preattestations with non-minimal slots are filtered by mempool
    • !17485 (merged) - Proto: add Preattestations_aggregate operation
    • !17645 (merged) - Proto: preattestations with differnt slots are no-longer slashed
    • !17734 (merged) - Proto: implement Preattestations_aggregate validation
    • !17853 (merged) - Proto: implement Preattestations_aggregate application
    • !17860 (merged) - Proto/test_aggregate: add unit testing for preattestations_aggregate protocol implementation
    • !17877 (merged) - Baker: aggregate preattestations
    • !17884 (merged) - Proto/validate: a valid block includes at most one preattestations_aggregate
    • !17890 (merged) - Proto/validate: eligible operations must be aggregated

  • Misbehaviours regarding Attestations_aggregates are denounced #7598 (closed)

    • do not denounce different slots regardless of feature flag @4dam !18043 (merged) !18040 (merged) !18049 (merged)
    • update denunciation operation types and validation/application to cover aggregates @dianegalloiswong !18073 (merged) !18032 (merged) !18103 (merged)
    • update accuser to denounce aggregates !18091 (merged)
    • update DAL node to handle aggregates @GuillaumeGen !18057 (merged)

• Performance measurement

  • Benchmark of signatures aggregation
    • MinPK VS MinSig
  • Benchmark of signatures aggregation check
    • MinPK VS MinSig
    • POP aggregate verify
  • Block space footpring measurement
  • Block bandwidth measurement