jsnark and xjsnark for ethsnarks

This repository provides an example of integrating jsnark circuits with EthSnarks. It allows you to construct circuits using jsnark and xjsnark which can be proven on Ethereum.

Checkout this repository into the same parent directory that contains ethsnarks:

• project-root
  • ethsnarks
  • ethsnarks-jsnark

How it Works

jsnark and xjsnark output two files:

• Circuit instructions (ending in .arith)
• Input values (ending in .in)

EthSnarks ships with an executable called pinocchio, this takes the .arith and .in files to generate the proving and verification keys for the circuit, and then to create a proof.

Evaluate the circuit and its inputs

pinocchio mycircuit.arith eval mycircuit.in

Generate proving key

Generates proving key file named mycircuit.pk and verification key named mycircuit.vk.json

pinocchio mycircuit.arith genkeys mycircuit.pk mycircuit.vk.json

Create proof

Uses the proving key mycircuit.pk to create a proof named mycircuit.proof.json for the inputs mycircuit.in

pinocchio mycircuit.arith prove mycircuit.in mycircuit.pk mycircuit.proof.json

Verify proof

Uses the verification key mycircuit.vk.json and the proof mycircuit.proof.json

pinocchio mycircuit.arith verify mycircuit.vk.json mycircuit.proof.json

Notes

The jsnark tool could be improved in the following ways:

1. It's not necessary to output the values for every variable if the operations are evaluated
2. Public inputs must be specified first in the circuit .arith file

The pinocchio tool could be improved in the following ways:

1. If all variable values are provided by jsnark, there's no need to evaluate the circuit