gkr-backend

Multivariate polynomial primitives for GKR-based proving systems. Built on Plonky3 field arithmetic.

Crates

Crate	Description
sumcheck	Sumcheck prover and verifier — linear-time, linear-space via CTY11/Thaler13-style in-place halving
mpcs	Multilinear polynomial commitment schemes (BaseFold, WHIR)
multilinear_extensions	Multilinear polynomials in dense evaluation form — variable binding, point evaluation, eq(x,r) construction
transcript	Fiat-Shamir transcript trait and Poseidon2-based implementation (observe, squeeze challenges, fork for parallel proving)
ff_ext	Thin trait layer over Plonky3 fields — adds uniform byte sampling, canonical conversions, and Poseidon2 configuration for Goldilocks and BabyBear
poseidon	Default Poseidon2 challenger wrapper with optional permutation-count instrumentation (debug builds)
p3	Re-exports Plonky3 crates under a single namespace for unified version pinning and feature propagation
whir	WHIR polynomial commitment scheme (forked from WizardOfMenlo/whir)
sumcheck_macro	Proc macro that generates degree-specialized sumcheck inner loops with compile-time unrolling
witness	Row-major witness matrix with power-of-two padding and column-to-MLE extraction
curves	Elliptic curve definitions and scalar multiplication — Secp256k1, Secp256r1, BN254, Ed25519, BLS12-381 (forked from SP1)

Build and test

# Format and lint
cargo fmt --all -- --check
cargo clippy --workspace --all-targets --all-features -- -D warnings

# Test — serial (client-side proving)
cargo test --workspace --lib

# Test — parallel + SIMD (server-side production)
cargo make tests

Requires Rust nightly (nightly-2025-08-18). See rust-toolchain.toml.