Groth16 Prover

WARNING: This software is still experimental, we do not recommend it for production use (see Security section).

This directory contains utilities for performing a "stark2snark" workflow. This is useful for transforming a RISC Zero STARK proof into a Groth16 SNARK proof which is suitable for publishing on-chain.

Quickstart

To install the necessary dependencies, run:

./scripts/install_prover.sh

Manual installation

All the following commands must be run from the compact_proof directory.

1. Build circom files and binaries:

docker build -f docker/build.Dockerfile . -t snark-build --output=groth16 --target outputs

2. Copy the stark_verify_final.zkey from a ceremony into the groth16 directory. Alternatively, run the ceremony (optional):

wget -O groth16/pot23.ptau https://hermez.s3-eu-west-1.amazonaws.com/powersOfTau28_hez_final_23.ptau
docker build -f docker/ceremony.Dockerfile . -t snark-ceremony
docker run --rm -v $(pwd)/groth16:/ceremony/groth16 snark-ceremony

3. Build the prover image:

docker build -f docker/prover.Dockerfile . -t risc0-groth16-prover

Proof Generation

The input.json file needs to be generated using the seal-to-json utility. Place this file into the directory of your choice, then add this as a volume and run the docker container:

docker run --rm -v $WORK_DIR:/mnt risc0-groth16-prover

The resulting proof.json file will be in the chosen $WORK_DIR. This file can be parsed and decoded into a risc0_groth16::Seal. Finally, this seal can be embedded within a InnerReceipt::Compact.

See risc0-groth16/src/tests/stark_to_snark.rs for an end-to-end example.