ETH2 Validator private messaging PoC (WIP)

Description

Minimal bare-bone example which implements a messaging client for a Private message sharing channel for ETH2 validators. It demos how the clients can register and share messages with various content anonymously. For the messaging part the Waku V2 protocol is used, more specifically the Waku-js implementation. The RLN messages are implemented outside of the library, but according to the Waku RLN-Relay protocol. The goal is to implement all of the things related to RLN inside the RLN-Relay protocol, as part of the Waku-js library. Currently only the basic flow is implemented, without verifying that the clients are active ETH2 validators. The same BLS signature stnadard is used as in the ETH2 spec.

Implementation spec

The spam limit is set to 1, thus the users will be slashed if they send more than 1 message per epoch. The epoch choice is a UNIX UTC timestamp representation of the minute that the message is being sent in. Merkle tree of depth 32 is being used. MongoDB is being used for storing the Membership merkle tree at each peer. Additionally database domain separation is implemented, so multiple clients can be hosted on the same machine. RLN circuits from the following repository are used: https://github.com/appliedzkp/rln.

For membership registration, each peer listens to events from the RegistryContract. Upon each received event, the signature is validated an the id commitment is inserted into the peer's membership merkle tree, if the user is not already registered and if the user is not banned.

The above parameters are used just for demo purposes, they should be tweaked for in-production usage.

Requirements

RPC access to Ethereum node (for RegistryContract events)
MongoDB connection
(Soon) Being an active ETH2 validator

Test usage

Copy .env.example into .env and set it up properly
Deploy the RegistryContract, to a local network (After cloning and installing the dependencies from the RegistryContract repository, start a local chain: yarn chain and deploy the contract yarn deploy --network localhost).
docker-compose up -d (this will run a test mongodb instance)
yarn install
yarn test basic || yarn test spam

TODO