Proposal: Semaphore ERC7579 Validator Module

[jimmychu0807]

PSE Acceleration Program

• Project: Semaphore ERC7579 Validator Module
  Project Idea: Semaphore + Account Abstraction semaphore-protocol/semaphore#345

Project Overview 📄

Overview

Semaphore is a zero knowledge component that allows users to prove their group membership and send signals without revealing their original identity.

With the recent development of Account Abstraction ERC-4337 and Minimal Modular Smart Account ERC-7579, these advancements allow a smart account to install modules to gain extra functionalities.

The objective of this accelerator program proposal is to develop a Semaphore ERC-7579 validator module so when this module installed, the smart account allows Semaphore group members (of that particular account) to sign transactions on behalf of the account. I will also integrate MultiFactor validator so a transaction requires a M (1<=M<=N) of N member zk-proof, behaving like a multisig wallet. M is configurable by the Semaphore group admin.

One advantage of this setup compared to a normal multisig wallet is that signers' privacy is preserved. Because of the smart account interaction model, the original transaction initiator sends http/RPC requests to a bundler, and the bundler in turn sends the transaction on-chain with paymaster configured to pay for the tx fee. So we won't be able to trace who the original transaction initiator is.

Project Details

The idea of this project has been explored by Saleel, and is documented in his blogpost. It was built at a time when the tool stack was still primitive. In this proposal, I aim to formalize this and solve semaphore-protocol/semaphore#345. When a smart account owner install this Semaphore ERC-7579 module to a smart account, a new Semaphore group is created. The user becomes the admin of the group and can manage the members inside. Any members in the Semaphore group will be able to send a zk proof of transaction on behalf the smart account. This is like a 1/N mult-sig wallet, with N being the number of members in the Semaphore group.

Next, MultiFactor validator will be integrated to work with Semaphore validator to make it behave as a M of N multisig wallet. This module will be integrated via ModuleSDK to demonstrate the composibility of ERC-7579 modules.

At the end of the proposal, the following will be delivered:

1. Semaphore ERC7579 validator module, making it a 1-of-N wallet.
2. Integration with MultiFactor validator, making it a M-of-N wallet.
3. End-to-end test code for testing the following behaviors:
   • installing the module to a smart account
   • admin adding/removing members, switching admins
   • sending transactions with M of N member signatures
   • uninstalling the module from the smart account
4. Inline code documentation.
5. A front-end demo allowing users to install this module to their smart accounts, add members (identity commitments) to the semaphore group, and sending zk proofs, all happening on a chosen testnet.
6. A writeup to introduce what has been done and give a technical overview of the module.

Team 👥

Team members

• Jimmy Chu
  Email: [email protected]
  Telegram: @jimmychu0807
  Discord: @jimmychu0807

Team Website

website: https://jimmychu0807.hk/

Team's experience

I participated in the PSE Core Program 2024 - Taiwan, and delivered a capstone project of a zero-knowledge Number Guessing Game, built upon Semaphore boilerplate.

I previously worked in Parity as Polkadot developer advocate and CESS as developer advocate advisor. Other prior experience can be seen in my GitHub profile.

Team Code Repos

https://github.com/jimmychu0807

Development Roadmap 🔩

Overview

• Total Estimated Duration: 4 weeks
• Full-time equivalent (FTE): 1
• Total Cost:: $10,000
• Expected Start Date:
• Expected End Date:

Milestone 1: M-of-N Semaphore validator module

• Estimated Duration: 2 weeks
• FTE: 1
• Cost: $5,000
• Estimated delivery date:

Deliverables and Specifications

1. Semaphore ERC7579 validator module

It will be a module in ModuleKit validator. Semaphore and related contracts will be deployed to be used in the validator module. With this module, the smart account behave like an 1-of-N multisig wallet.

2. Integration with MultiFactor validator

Using ModuleSDK to integrate MultiFactor validator with Semaphore validator developed above. With this integration, the smart account will behave like an M-of-N multisig wallet.

3. End-to-end test code

Both hardhat and foundry test will be written to cover 85% of the Solidity code for unit tests. Local development environment can also be spin up by Docker-compose to run end-to-end test of the module.

4. Inline code documentation

All public functions of the module contract will be documented according to NatSpec format.

Milestone 2: Front-end demo, deployment scripts, and writeup

• Estimated Duration: 2 weeks
• FTE: 1
• Cost: $5000
• Estimated delivery date:

Deliverables and Specifications

5. Front-end demo & deployment scripts

A front-end demo will be able to spin up locally with a single yarn command. Because it relies on existing EntryPoint singleton and Paymaster contract to work, the locally running front end will need to connect to a testnet in order to execute all the functionality of the module.

Deployment scripts will be developed for front end being deployed to Vercel hosting and smart contracts deployed on a chosen testnet.

6. Writeup

A writeup will be submitted for review giving a technical overview of the project.

Additional Information ➕

• Thanks @JohnGuilding for the proposal feedback in the issue thread.

• Currently exploring integrating Semaphore in ModuleKit in repo: https://github.com/jimmychu0807/rhinestone-modulekit-tut

[JohnGuilding]

Nice thanks for proposing this @jimmychu0807 :)

The proposal in general looks good to me.

admin adding/removing members, switching admins

Does this point imply that the module can be kept in sync with the semaphore group? Just want to make sure that this is covered in this proposal. E.g. removing group member can be reflected in smart account, and deciding if removing validator would want to be reflected in semaphore group

[jimmychu0807]

Does this point imply that the module can be kept in sync with the semaphore group? Just want to make sure that this is covered in this proposal. E.g. removing group member can be reflected in smart account, and deciding if removing validator would want to be reflected in semaphore group

Yes, the module is kept in sync with the semaphore group members. Only the zk-proof from the group members are counted as a valid "signature" for the smart account transaction.

[jimmychu0807]

@JohnGuilding Would like to know what is the next step of the application? And what is the general timeline of when I hear back from the vetting committee if the application passes? Thanks.

[JohnGuilding]

Hey @jimmychu0807, thanks for getting back.

Yes, the module is kept in sync with the semaphore group members

Great :)

Would like to know what is the next step of the application? And what is the general timeline of when I hear back from the vetting committee if the application passes?

So we will take a look at the application and get back to you, and if there is anything else you need to do we will also let you know! Due to Devcon we are pretty busy right now, so there will be a delay getting back to you unfortunately. I'm not sure what this timeline would be but it would be sometime after Devcon week (11th-17th) - so towards the end of November.