Simple Tornado

This is a simple version of Tornado Cash which is a private transactions solution based on zkSNARKs. The project rewrites from tornado-core, and it's suitable for a beginner to learn development of applications with Zero Knowledge Proofs.

Tech Stack

• circom 0.5.45
• snarkjs 0.4.4
• circomlib 0.5.2
• solidity 0.7.0
• ethers: 5.0.26
• hardhat
• typescript

Pre-requisites

• install Node.js with cmd node
• Install circom and snarkjs as global command-line

npm install -g circom
npm install -g snarkjs

Build

• install dependencies

yarn

• pre-requisites: circom and snarkjs as global command-line

yarn build

Test

• pre-requisites: run yarn build for circuits and Hasher.json

yarn test

or

npx hardhat test test/FILENAME.test.ts

Questions

• why we need FIELD_SIZE and ZERO_VALUE in the merkle tree? (seems to be called "snark scalar field")
• Is it possible to have nullifier equal to secret? (this project implements like this but the original tornado-core divide nullifier and secret)