# Zero-Knowledge Wormholes (EIP-7503) Implementation

This repository contains an implementation of [EIP-7503: Zero-Knowledge Wormholes](https://eips.ethereum.org/EIPS/eip-7503), a native privacy solution for Ethereum.

**Repository:** [https://github.com/neotheprogramist/go-ethereum/tree/v1.15.11/eip-7503](https://github.com/neotheprogramist/go-ethereum/tree/v1.15.11/eip-7503)

## Overview

Zero-Knowledge Wormholes provide a privacy mechanism that allows users to privately transfer ETH by:

1. **Burning ETH** by sending it to an unspendable address derived from a secret
2. **Later minting** the same amount back using zero-knowledge proofs

The implementation offers strong privacy guarantees with plausible deniability, as there's no on-chain evidence of participation in the privacy protocol. It creates an anonymity pool that includes all Ethereum accounts with zero outgoing transactions by default.

## Components

### 1. Zero-Knowledge Circuit

The Noir circuit (`wormhole/src/main.nr`) implements the ZK-proof logic defined in EIP-7503:

- Validates deposit value limits (max 32 ETH)
- Generates nullifiers to prevent double-spending
- Verifies proof of work to prevent hash collision attacks
- Confirms Merkle proof membership
- Ensures value conservation (withdraw + change = deposit)

### 2. Go API

The Go API (`internal/ethapi/mint.go`) handles minting operations:

- Verifies ZK proofs using an external verification tool
- Tracks nullifiers in a database to prevent double-spending
- Creates and signs transactions to mint tokens
- Manages nullifier state

### 3. Testing Framework

Comprehensive tests (`internal/ethapi/mint_test.go`) validate:

- Basic minting operations
- Double-spend prevention using nullifiers
- Error handling for invalid proofs or parameters
- Tampered proof detection

## How It Works

1. **Deposit**: Users send ETH to an address derived from their secret: `sha256(MAGIC_ADDRESS + secret)[12:]`
2. **Generate Proof**: Users create a ZK proof showing they know a secret for funds in an unspendable address
3. **Withdraw**: Users present their proof to mint back their ETH to a new address, without revealing the link between deposit and withdrawal

## Security Features

- **Nullifier Registry**: Prevents double-spending of burnt ETH
- **Proof of Work**: Requires computational work to prevent hash collision attacks
- **Privacy Pools**: Optional mechanism for responsible privacy usage
- **Value Splitting**: Ability to withdraw only part of a deposit, with the remainder going to a change output

## Usage

The implemented API allows for:

- Minting ETH using ZK proofs
- Verifying proofs before allowing mints
- Tracking used nullifiers to prevent double-spending