zama-fhevm-with-openzeppelin-upgrades

name: zama-fhevm-with-openzeppelin-upgrades description: Production-grade v6.1.0 elite guide to fhevm with openzeppelin upgrades on Zama FHEVM. category: Foundation difficulty: Advanced version: "6.1.0"

Zama FHEVM WITH OPENZEPPELIN UPGRADES

Overview

This skill provides a comprehensive, production-grade implementation of fhevm with openzeppelin upgrades using Zama's Fully Homomorphic Encryption (FHE) Virtual Machine.

Architecture

mermaid graph TD User[User / AI Agent] -->|Encrypted Input| SC[Smart Contract] SC -->|Symbolic Task| Coprocessor[Coprocessor] Coprocessor -->|FHE Computation| KMS[KMS / Gateway] KMS -->|Encrypted Result| SC

Prerequisites

• Mastery of encrypted types (euint8, euint32, etc.).
• Understanding of the Zama Gateway and Coprocessor architecture.

Full Implementation

Smart Contract Logic

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

import { FHE, euint32, ebureau } from "@fhevm/solidity/lib/FHE.sol";

contract fhevmwithopenzeppelinupgrades { // Encrypted state variable euint32 private secretData;

constructor() {
    secretData = FHE.asEuint32(0);
}

// Core business logic for fhevm with openzeppelin upgrades
function executeTask(bytes calldata encryptedInput) public {
    euint32 input = FHE.asEuint32(encryptedInput);
    
    // Branchless logic using FHE.select
    secretData = FHE.select(FHE.gt(input, secretData), input, secretData);
    
    // Ensure availability
    FHE.allow(secretData, msg.sender);
}

} `

Deployment to Sepolia

1. Configure your hardhat.config.ts with the Zama Sepolia RPC.
2. Run the deployment script: ash npx hardhat run scripts/deploy.ts --network sepolia

Security Checklist

• No Branching: Ensure no if or while statements rely on decrypted values.
• Input Proofs: Validate all user-provided encrypted handles using FHE.asEuintXX.
• Access Control: Use FHE.allow() and FHE.isAllowed() to manage visibility.

Common Pitfalls & Fixes

• Handle Expiration: FHE handles are ephemeral; do not store them off-chain for long periods.
• Gas Costs: FHE operations are computationally expensive; batch operations where possible.

AI Agent Prompt

"Act as a Zama FHEVM Senior Architect. Review this fhevm with openzeppelin upgrades implementation. Focus on identifying potential information leaks through gas usage patterns or incorrect application of the branchless programming paradigm."