Library Installation and Overview

This section contains comprehensive guides and examples for using OpenZeppelin's confidential smart contracts library with FHEVM. OpenZeppelin's confidential contracts library provides a secure, audited foundation for building privacy-preserving applications on fully homomorphic encryption (FHE) enabled blockchains.

The library includes implementations of popular standards like ERC7984, adapted for confidential computing with FHEVM, ensuring your applications maintain privacy while leveraging battle-tested security patterns.

Getting Started

This guide will help you set up a development environment for working with OpenZeppelin's confidential contracts and FHEVM.

Prerequisites

Before you begin, ensure you have the following installed:

• Node.js >= 20

• Hardhat ^2.24

• Access to an FHEVM-enabled network and the Zama gateway/relayer

Project Setup

1. Clone the FHEVM Hardhat template repository:

   git clone https://github.com/zama-ai/fhevm-hardhat-template conf-token
   cd conf-token

2. Install project dependencies:

   npm ci

3. Install OpenZeppelin's confidential contracts library:

   npm i @openzeppelin/confidential-contracts

4. Compile the contracts:

   npm run compile

5. Run the test suite:

   npm test

FHEVM v0.9 API Changes

This documentation has been updated for FHEVM v0.9. Key changes include:

• Solidity version: pragma solidity ^0.8.27

• Import paths: Updated to match new OpenZeppelin Confidential Contracts structure

• Decryption API:

  • Old: FHE.requestDecryption() (deprecated)

  • New: FHE.makePubliclyDecryptable() + FHE.checkSignatures()

• Config: Use ZamaEthereumConfig for network configuration