keccak256-circom/README.md

keccak256-circom

Keccak256 hash function (ethereum version) implemented in circom. Spec: https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf

Warning: WIP, this is an experimental repo.

Status

Initial version works, compatible with Ethereum version of Keccak256.

It needs around 150848 (151k) constraints.

For context: Rapidsnark proof generation time:

• 1.1M constraints -> 7 seconds (8 CPU)
• 128M constraints -> <2min (64 CPU)

Usage

• import the lib in the package.json:

"dependencies": {
	"keccak256-circom": "git+https://github.com/vocdoni/keccak256-circom"
}

• Usage:

pragma circom 2.0.0;

include "../node_modules/keccak256-circom/circuits/keccak.circom";

// for a input & output of 32 bytes:
component main = Keccak(32*8, 32*8);