/go-kzg

FFT, data-recovery and KZG commitments, a.k.a. Kate commitments, in Go - *super experimental*

Primary LanguageGoMIT LicenseMIT

KZG and FFT utils

This repo is super experimental.

This is an implementation in Go, initially aimed at chunkification and extension of data, and building/verifying KZG proofs for the output data. The KZG proofs, or Kate proofs, are built on top of BLS12-381.

Part of a low-latency data-availability sampling network prototype for Eth2 Phase 1. See https://github.com/protolambda/eth2-das

Code is based on:

Features:

  • (I)FFT on F_r
  • (I)FFT on G1
  • Specialized FFT for extension of F_r data
  • KZG
    • commitments
    • generate/verify proof for single point
    • generate/verify proofs for multiple points
    • generate/verify proofs for all points, using FK20
    • generate/verify proofs for ranges (cosets) of points, using FK20
  • Data recovery: given an arbitrary subset of data (at least half), recover the rest
  • Optimized for Data-availability usage
  • Change Bignum / BLS with build tags.

BLS

Currently supported BLS implementations: Herumi BLS and Kilic BLS (default).

Field elements (Fr)

The BLS curve order is used for the modulo math, different libraries could be used to provide this functionality. Note: some of these libraries do not have full BLS functionality, only Bignum / uint256. The KZG code will be excluded when compiling with a non-BLS build tag.

Build tag options:

  • (no build tags, default): Use Kilic BLS library. Previously used by bignum_kilic build tag. kilic/bls12-381
  • -tags bignum_hbls: use Herumi BLS library. herumi/bls-eth-go-binary
  • -tags bignum_hol256: Use the uint256 code that Geth uses, holiman/uint256
  • -tags bignum_pure: Use the native Go Bignum implementation.

Benchmarks

See BENCH.md for benchmarks of FFT, FFT in G1, FFT-extension, zero polynomials, and sample recovery.

License

MIT, see LICENSE file.