fhEVM dApp Examples

This repository contains example dApps built using fhEVM (Fully Homomorphic EVM). Each example demonstrates different aspects of building privacy-preserving smart contracts using FHE operations.

Project Structure

The repository contains two main components:

• /hardhat - Smart contract examples and development environment
• /confidentialTransfer - React-based frontend dApp for confidential token transfers

NOTE: /confidentialTransfer folder is currently still outdated and it's not v0.7, but v0.6

Smart Contract Examples

The /hardhat folder contains several privacy-preserving smart contract examples:

Basic FHE Operations

• Encryption/Decryption - Examples of encrypting and decrypting values
• FHE Operators - Basic homomorphic operations like addition and conditional logic
• User Decrypt - User-side decryption examples
• Decrypt in Solidity - On-chain decryption capabilities

Advanced Applications

• Confidential Counter - Progressive examples demonstrating FHE operations from basic to multi-user counters
• FHE Wordle - Privacy-preserving word guessing game using encrypted letter comparisons
• Confidential Auctions - Multiple auction implementations with encrypted bids:
  • Blind auctions with sealed bids
  • Dutch auctions with descending prices

Token & Wrapper Contracts

• Confidential Token Example - Mock confidential token for testing
• ERC20 Wrapper - Wrapper for standard ERC20 tokens
• ETH Wrapper - Wrapper for native ETH
• Faucet Contract - Test token distribution contract

Mock Contracts

• Mock USDZ - Mock stablecoin implementation
• Prize Item - Mock NFT-like contract

Each example includes detailed documentation in its respective README explaining the implementation and FHE usage.

Contributing

This repository serves as a comprehensive example of building privacy-preserving dApps with fhEVM. Feel free to explore the examples, run the tests, and use them as a foundation for your own projects.

License

This project is licensed under the BSD-3-Clause-Clear license.