daggerChat

A blockchain-based secure chat application with end-to-end encryption and a terminal UI. Messages are encrypted locally and stored on the Ethereum blockchain (Arbitrum L2), ensuring privacy and immutability.

Table of Contents

• Screenshots
• Features
• Installation
• Configuration
• Usage
• Keyboard Shortcuts
• Smart Contract
• Security
• Project Structure
• Contributing
• Acknowledgments
• Author

Screenshots

Features

• End-to-end encryption - X25519 key exchange + XChaCha20-Poly1305 encryption
• Decentralized storage - Messages stored on Arbitrum (Ethereum L2)
• Wallet authentication - Login with your Ethereum wallet
• Direct messaging - Private 1-on-1 encrypted chats
• Group chats - Create groups with shared encryption keys
• Terminal UI - Fast, keyboard-driven interface
• Offline support - Queue messages when offline, sync when connected
• Local caching - SQLite database for fast message access

Installation

Prerequisites

• Rust 1.75 or later
• An Ethereum wallet with some ETH on Arbitrum (for gas fees)
• An RPC endpoint (Alchemy, Infura, or public RPC)

Build from source

# Clone the repository
git clone https://github.com/mantreshkhurana/daggerChat.git
cd daggerChat

# Build the project
cargo build --release

# The binary will be at ./target/release/dagger-chat

Configuration

Create a .env file in the project root (or copy from .env.example):

# Arbitrum RPC endpoint
RPC_URL=https://arb-mainnet.g.alchemy.com/v2/YOUR_API_KEY

# Your wallet private key (without 0x prefix)
# WARNING: Never commit your actual private key!
PRIVATE_KEY=your_private_key_here

# DaggerChat contract address (after deployment)
CONTRACT_ADDRESS=0x...

# Log level
LOG_LEVEL=info

Usage

# Run with .env configuration
./target/release/dagger-chat

# Or specify options directly
./target/release/dagger-chat --rpc-url https://... --wallet 0x...

# Enable debug logging
./target/release/dagger-chat --debug

Keyboard Shortcuts

Key	Action
Tab	Switch between sidebar and chat
j/k or ↑/↓	Navigate conversations/messages
Enter	Select conversation / Send message
n	New conversation
g	Create group
Ctrl+W	Wallet info
Ctrl+R	Force sync
Esc	Go back / Cancel
q or Ctrl+Q	Quit

Smart Contract

The DaggerChat.sol contract is deployed on Arbitrum and provides:

• User registration with X25519 public keys
• Encrypted message storage
• Batch message sending (gas optimization)
• Group chat management
• Event-based message indexing

Deploy the contract

# Using Foundry
forge create --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY \
  contracts/DaggerChat.sol:DaggerChat

# Or using Hardhat/Remix

Security

• Private keys: Never stored; only used for signing
• Message encryption: XChaCha20-Poly1305 with per-message nonces
• Key exchange: X25519 ECDH for DMs, shared symmetric keys for groups
• Local storage: Encryption keys protected with password-derived keys

Project Structure

daggerChat/
├── Cargo.toml              # Rust dependencies
├── contracts/
│   └── DaggerChat.sol      # Solidity smart contract
├── migrations/
│   └── 001_initial.sql     # SQLite schema
└── src/
    ├── main.rs             # Entry point
    ├── app.rs              # Application state
    ├── config.rs           # Configuration
    ├── errors.rs           # Error types
    ├── blockchain/         # Ethereum integration
    ├── chat/               # Chat logic
    ├── crypto/             # Encryption
    ├── storage/            # Local SQLite
    └── tui/                # Terminal UI

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - see LICENSE for details.

Acknowledgments

• Alloy - Ethereum SDK for Rust
• ratatui - Terminal UI framework
• RustCrypto - Cryptography libraries

Author

• Mantresh Khurana