ZKSDK EVM Co-Processor

Singleton co-processor contracts for FHE computations on EVM chains.

Overview

This package contains the EVM implementation of the ZKSDK Co-Processor, which:

• Receives encrypted computation requests from vault contracts
• Emits events for the off-chain listener to process
• Posts encrypted results back on-chain
• Callbacks to vault contracts with results

Contracts

| Contract | Description | |----------|-------------| | ZKSDKCoProcessor.sol | Singleton co-processor (deployed to same address on all chains) | | CoProcessorClient.sol | Base contract for vaults to inherit | | IZKSDKCoProcessor.sol | Interface for the co-processor | | ICoProcessorCallback.sol | Callback interface for vault contracts |

Quick Start

# Install dependencies
npm install

# Compile contracts
npm run compile

# Run tests
npm test

Deployment

Contracts are deployed using Hardhat Ignition with CREATE2 for deterministic addresses.

Deploy to Testnet

# Set up environment
cp .env.example .env
# Edit .env with your keys

# Deploy to Sepolia
npm run deploy:sepolia

# Deploy to other testnets
npm run deploy:polygon-amoy
npm run deploy:arbitrum-sepolia
npm run deploy:base-sepolia

# Verify all addresses match
npm run verify-addresses

Manual Deployment

npx hardhat ignition deploy ignition/modules/ZKSDKCoProcessor.ts \
  --network sepolia \
  --strategy create2 \
  --parameters ignition/parameters.json \
  --verify

Integration Example

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@zksdk/evm-coprocessor/contracts/CoProcessorClient.sol";

contract MyVault is CoProcessorClient {
    string public balanceBlobCid;

    constructor(address coProcessor) CoProcessorClient(coProcessor) {}

    function privateTransfer(
        address receiver,
        string calldata encryptedDataCid
    ) external returns (bytes32) {
        bytes memory metadata = abi.encode(msg.sender, receiver);
        return _submitRequest("cmux_token_v1_linear", encryptedDataCid, metadata);
    }

    function _onResult(bytes32, string calldata resultCid) internal override {
        balanceBlobCid = resultCid;
    }

    function _onError(bytes32, string calldata) internal override {
        // Handle error
    }
}

Architecture

Vault Contract → ZKSDKCoProcessor → Event Emitted → Listener → FHE Worker
                                                            ↓
Vault Callback ← ZKSDKCoProcessor ← postResult() ← Listener ←

Networks

Testnets

• Sepolia (Ethereum)
• Polygon Amoy
• Arbitrum Sepolia
• Base Sepolia
• Optimism Sepolia

Mainnets

• Ethereum
• Polygon
• Arbitrum
• Base
• Optimism

License

MIT