Safe Anonymization Mail Module Circuits

This repository contains the circuit part of the SAMM project.

Description

This implementation of the circuits is for the Noir grant.

Our main concept revolves around creating a module for the Safe multisig that ensures the anonymity of all its participants using ZK-SNARK technology.

The details are outlined in:

• Technical docs
• Grant Proposal

Repository structure

This repository consists of several parts:

• lib folder - contains the samm Nargo library which implements the main logic of SAMM.
• builds folder - contains two Nargo bin projects: samm_1024, samm_2048. Both projects are built on top of the samm library and differ only in the size of the public key in the DKIM signature.
• helpers folder - contains auxiliary scripts needed for preparing data for tests.

Dependencies

The circuits are written in Noir and use the Barretenberg proving library. To work correctly, the following versions are required:

• Noir v0.35.0
• BB v0.57.0

Install the required version of Noir

1. Open a terminal on your machine, and write:

       curl -L https://raw.githubusercontent.com/noir-lang/noirup/main/install | bash
   

2. Close the terminal, open another one, and run:

       noirup -v v0.35.0
   

Done. That's it. You should have the latest version working. You can check with nargo --version. Complete instructions for installing Noir and Nargo can be found here.

Install the required version of Barretenberg (BB)

1. Install bbup the installation script by running this in your terminal:

       curl -L https://raw.githubusercontent.com/AztecProtocol/aztec-packages/master/barretenberg/cpp/installation/install | bash
   

2. Reload your terminal shell environment.
3. Install the version of bb compatible with your Noir version:

       bbup -v 0.57.0
   

4. Check if the installation was successful:

       bb --version
   

Complete instructions for installing Barretenberg can be found here.

Compilation

To compile a nargo project (separately in the folders ./lib, ./builds/samm_2048, ./builds/samm_1024):

  nargo compile

Run tests

To run the tests (separately in the folders ./lib, ./builds/samm_2048, ./builds/samm_1024):

  nargo test

Generate/verify proof

1. Open one of the builds (1024 or 2048 signature) by running:

       cd builds/samm_2048
   

   or

       cd builds/samm_1024
   

2. Generate a witness for your Noir program by running:

       nargo execute witness-samm
   

3. Prove the valid execution of your Noir program by running:

       bb prove_ultra_honk -b ./target/samm_2048.json -w ./target/witness-samm.gz -o ./target/proof
   

   For the Solidity Verifier, run:

       bb prove_ultra_keccak_honk -b ./target/samm_2048.json -w ./target/witness-samm.gz -o ./target/proof2048
   

   Or for the 1024 signature:

       bb prove_ultra_honk -b ./target/samm_1024.json -w ./target/witness-samm.gz -o ./target/proof
   

   and

       bb prove_ultra_keccak_honk -b ./target/samm_1024.json -w ./target/witness-samm.gz -o ./target/proof1024
   

4. Compute the verification key for your Noir program by running:

       bb write_vk_ultra_honk -b ./target/samm_2048.json -o ./target/vk
   

   Or for the 1024 signature:

       bb write_vk_ultra_honk -b ./target/samm_1024.json -o ./target/vk
   

5. Verify your proof by running:

       bb verify_ultra_honk -k ./target/vk -p ./target/proof
   

   If successful, the verification will complete silently; if unsuccessful, the command will trigger logging of the corresponding error.

6. Generate the Solidity Verifier contract:

       bb contract_ultra_honk -k ./target/vk -c $CRS_PATH -b ./target/samm_2048.json -o ./target/Verifier2048.sol
   

   Or for the 1024 signature:

       bb contract_ultra_honk -k ./target/vk -c $CRS_PATH -b ./target/samm_1024.json -o ./target/Verifier1024.sol
   

Helpers

The helpers folder contains auxiliary scripts needed for preparing data for tests, specifically for generating a custom Prover.toml file. Note that the prepared Prover.toml files are already located in the folders ./builds/samm_2048 and ./builds/samm_1024, so this step is optional.

Disclaimer: The code in the Helpers folder was only used for development and should never be run in production. Also, this code should not be subject to an audit.

Parse email

The email_parser project allows you to extract part of the public signals for the Prover.toml file from an email.

To do this, go to the necessary folder:

    cd helpers/email_parser

and run the script:

    cargo run --release

As a result, you will get a Prover_email.toml file with circuit's input signals inside. This file should be combined with the Prover_tree.toml from the member_tree_generator to compile the resulting Prover.toml.

Generate Merkle Tree

The member_tree_generator project allows generating a Merkle tree proof for a specific member of SAMM.

To run this, go to the necessary folder:

    cd helpers/member_tree_generator

Install the dependencies:

    npm install

And run the script:

    npx run scripts/generateDataForTest.js

As a result, you will get a Prover_tree.toml file with a Merkle proof (circuit's input signal) inside. This file should be combined with the Prover_email.toml from the email_parser to compile the resulting Prover.toml.

Prepare proof for smart contract tests

Get proof for SC part tests:

  cat ./target/proof2048 | od -An -v -t x1 | tr -d $' \n' | sed 's/^.\{8\}//' | (read hex; echo "${hex:0:192}${hex:12864}")

Where 192 + 198 * 64 = 12864. 198 - number of public inputs.

Commit and pubkeyHash for SC part tests:

  cat ./target/proof2048 | od -An -v -t x1 | tr -d $' \n' | sed 's/^.\{8\}//' | (read hex; echo "${hex:12736:128}")

License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.