Akita PCS

Akita is a high-performance, modular lattice polynomial commitment scheme with transparent setup and post-quantum security.

Akita is the public scheme name for this implementation and the intended repository/package name is akita-pcs. The codebase is being decomposed into a focused akita-* crate family rather than remaining a single monolithic package.

The current workspace exposes the main ownership boundaries under crates/:

• akita-field, akita-serialization, and akita-algebra own foundational arithmetic, encoding, NTT, ring, and polynomial utilities.
• akita-transcript, akita-challenges, and akita-sumcheck own Fiat-Shamir transcripts, challenge sampling, and generic sumcheck machinery.
• akita-types owns shared proof, setup, schedule, layout, SIS, and commitment data shapes used by both roles.
• akita-planner is the Cfg-free schedule engine: generated table types, on-demand expansion, catalog identity validation, the schedule-search DP, and the offline table emitter. It sits below akita-config.
• akita-schedules stores the tracked generated schedule tables. Cargo features select which tables a build includes.
• akita-config owns concrete runtime config presets and the single CommitmentConfig policy trait. It depends on akita-schedules (select_schedule_for_key delegates to strict generated-catalog resolution).
• akita-setup owns config-backed setup construction and optional setup cache persistence.
• akita-verifier owns verifier replay without prover-only polynomial backends. It is directly <Cfg>-generic (depends on akita-config) and reaches generated schedule expansion transitively.
• akita-prover owns commitment, proving, setup expansion, recursive/ring-switch witness construction, and polynomial backends.
• akita-pcs is the umbrella package: it owns the end-to-end AkitaCommitmentScheme orchestration, re-exports the broad public surface, and hosts examples, benches, and integration tests. (There is no separate akita-scheme crate.)

Verifier-only consumers should prefer the slim role crates directly: akita-verifier for verification, akita-types for proof/setup/claim shapes, and akita-config for concrete schedule/config policy. The umbrella akita-pcs package is convenient for examples and end-to-end use, but it also pulls in prover-facing APIs.

Documentation

The Akita Book is the canonical target for narrative documentation (how the scheme works, how to use it, and the foundations). Most chapters are still stubs that cite source paths and specs to fold; until prose lands, integrators should read the Akita Book (start with book/src/how/architecture.md), book/src/usage/commitment-api.md, and profile/akita-recursion/README.md. Build the book locally with ./scripts/serve-book.sh (see book/README.md for the toolchain). AGENTS.md is the agent command runbook; docs/ holds maintainer contracts (crate graph, verifier contract, CI timing). specs/ holds design records (lifecycle in specs/PRUNING.md). Documentation guardrails (CI + PR comments) are in docs/documentation.md.

Generated Schedules

Builds that use schedules read generated family modules from crates/akita-schedules/src/generated/. Git tracks these deterministic planner outputs. Ordinary builds, formatting, Clippy, tests, and profile jobs use them as checked in. Regenerate them after changing planner policy, candidate search, or generated catalog structure:

scripts/generate-schedule-tables.sh

The dedicated all-schedules drift job regenerates the complete catalog and rejects any byte difference from the tracked files.

Lineage

Akita keeps the earlier implementation lineage explicit while giving the improved scheme its own name. This is also the line where planned protocol improvements over the original design live: faster verifier-oriented reductions via matrix-claim delegation, smaller large-field proofs via modulus switching and field-size lowering, and efficient zero-knowledge techniques under the Whiteout design direction.

Contributing

Major features and architectural changes should start with a short spec. See CONTRIBUTING.md and specs/TEMPLATE.md for the review workflow.

Acknowledgements

The CRT/NTT and small-prime arithmetic design in this repository is informed by the Labrador/Greyhound C implementation family. In particular, the pseudo-Mersenne profile uses moduli of the form q = 2^k - offset. Akita provides a Rust-native architecture and APIs, while drawing algorithmic inspiration from those implementations.