FHEZmail is a decentralized, privacy email platform on the Ethereum Sepolia testnet. Using Fully Homomorphic Encryption (FHE), all emails are encrypted on-chain, and only the sender and recipient can read their content.

---

🌐 Live Demo

• Testnet Smart Contract: 0xCB45011ca6B8CDce01792CBB9B4c999479E94a0E
• Frontend (Next.js/React): https://fhevm-zmail.netlify.app/ (or deploy your own)

---

📖 Project Overview

FHEZmail combines blockchain and FHE encryption to create an email system that is:

• Decentralized: All emails stored on-chain, no central server.
• Encrypted: Subjects and bodies encrypted with Fully Homomorphic Encryption.
• Threaded: Supports replies and forwards while preserving privacy.
• Organized: Emails sorted into Inbox, Sent, Archive, Star, Spam, Trash, and Read.

---

🏗 Technologies Used

Smart Contract (On-chain)

• Solidity 0.8.24
• Fully Homomorphic Encryption (FHE):
• SepoliaConfig – Preconfigured Sepolia testnet setup

Frontend (User Interface)

• React – Modern, responsive UI
• Next.js – Server-side rendering & optimized builds
• @zama-fhe/relayer-sdk – Integrates FHE encryption/decryption on FE

---

⚡ Key Features

1. Send Emails

   • Encrypts subject & body using FHE
   • Creates copies for sender (Sent) and recipient (Inbox)
   • Permission management for encryption

2. Reply

   • Replies within existing threads
   • Updates boxes and maintains encryption

3. Forward

   • Securely forward emails
   • Updates permissions for new recipients

4. Move Emails

   • Move emails between boxes
   • TRASH box is handled specially

5. View Emails & Threads

   • Fetch mails by box type
   • Fetch full threads with encrypted replies

---

🛠 Getting Started

Prerequisites

• Node.js >= 20
• Yarn or npm
• MetaMask or Web3 wallet
• Sepolia testnet ETH

Installation

git clone https://github.com/NarutoLab/fhevm-zama-mail-app.git
cd pakages/site
npm install

Running Frontend

npm run dev

Open http://localhost:3000 to access the dApp.

---

💻 Smart Contract Interaction

Contract Address: 0xCB45011ca6B8CDce01792CBB9B4c999479E94a0E

Key Functions:

// Send a new email
sendMail(to, subjectExternal, subjectProofs, bodyExternal, bodyProofs);

// Reply to a thread
reply(threadId, subjectExternal, subjectProofs, bodyExternal, bodyProofs);

// Forward an email
forward(mailId, to);

// Move emails between boxes
move(mailIds, newBox);

// Fetch emails
(inbox(user),
  sent(user),
  archive(user),
  star(user),
  spam(user),
  trash(user),
  read(user));

---

🌟 Future Potential

FHEZmail lays the foundation for next-gen decentralized communication:

• Cross-chain Encrypted Messaging
• Decentralized Identity Integration (ENS, DIDs)
• Encrypted Search & Filters without decryption

---

🔒 Security & Privacy

• Emails are encrypted on-chain; only allowed participants can decrypt
• No plaintext stored on-chain
• Full control of permissions using FHE primitives

---

Documentation

• Hardhat + MetaMask: Set up your local devnet step by step using Hardhat and MetaMask.
• FHEVM Documentation
• FHEVM Hardhat
• @zama-fhe/relayer-sdk Documentation
• Setting up MNEMONIC and INFURA_API_KEY
• React Documentation
• FHEVM Discord Community
• GitHub Issues

License

This project is licensed under the BSD-3-Clause-Clear License - see the LICENSE file for details.