noir VS tornado-core

mkdir -p $HOME/.nargo/bin && \ curl -o $HOME/.nargo/bin/nargo-x86_64-unknown-linux-gnu.tar.gz -L https://github.com/noir-lang/noir/releases/download/v0.17.0/nargo-x86_64-unknown-linux-gnu.tar.gz && \ tar -xvf $HOME/.nargo/bin/nargo-x86_64-unknown-linux-gnu.tar.gz -C $HOME/.nargo/bin/ && \ echo 'export PATH=$PATH:$HOME/.nargo/bin' >> ~/.bashrc && \ source ~/.bashrc

Noir, built by Aztec, is the newest language of the pack and is under active development. It is distributed as nargo, a rust-based CLI, and as a set of npm packages. The npm packages releases seem to lag slightly behind the crate, which has the bleeding edge features and only got its first stable release a few days ago (early February). Both the rust crate and the npm package can be used to compile Noir programs, generate and verify proofs, and create a verifier Solidity contract.

Noir.

This is the repo we’re going to look at: Tornado core.

The method that I’m using is the same as what is used by Tornado Cash. Tornado Cash is a non-custodial Ethereum and ERC20 privacy solution based on zkSNARKs.

Tornado Cash is a great learning resource on how to build a real-world zk-app with Circom circuits. I strongly recommend going through the 3-page-long white paper, as well as Gubsheep's breaking down Tornado Cash session from the 0xparc course, plus Porter's overview of the white paper.

This was my very short tutorial on using zk-SNARK in JavaScript. It’s not a full course, and you probably have many questions, but I hope I helped you to start your journey. Circom and snarkjs are well documented, and you can also learn a lot from existing projects like Tornado Cash.

This is the MerkleTree contract, and the problem is on lines 58 and 59, I cannot understand why would you need to veryfy that the hash of a number has to be less than FIELD_SIZE.