echat 0.1.0

End-to-end encrypted terminal chat using Diffie-Hellman key exchange and AES encryption

echat - Encrypted P2P Terminal Chat

A secure, end-to-end encrypted peer-to-peer chat application for your terminal. Built with Python using Diffie-Hellman key exchange and AES-256 encryption.

Features

• 🔗 True P2P Architecture - No central server, connect directly to peers
• 🔐 Diffie-Hellman Key Exchange - Secure key agreement without sharing secrets
• 🔒 AES-256 Encryption - Military-grade encryption using Fernet
• 🌐 Network Support - Works over local networks (LAN)
• 💬 Full-Duplex - Send and receive messages simultaneously
• 🖥️ Terminal-Based - No GUI needed, works in any terminal
• 📝 Connection Requests - Accept or reject incoming connections

Installation

git clone https://github.com/manikanta-adupa/EncryptedTerminalChat.git
cd echat
pip install -e .

Usage

Start echat

Both users run the same command:

echat

What You'll See

==================================================
  echat - Encrypted P2P Terminal Chat
==================================================

  Your IP: 192.168.1.100
  Listening on port: 9999

  Share your IP with others to let them connect.
==================================================

Options:
  1. Connect to a peer (enter their IP)
  2. Wait for incoming connections
  3. Exit

Enter peer IP to connect, or press Enter to wait:

Connecting to a Peer

User A (initiator):

Enter peer IP to connect, or press Enter to wait: 192.168.1.101
Connecting to 192.168.1.101:9999...
Waiting for peer to accept...
Connection accepted!
Establishing secure connection...
Secure connection established!
==================================================
  You can now chat securely. Type 'exit' to quit.
==================================================

User B (receiver):

==================================================
  Incoming connection from 192.168.1.100
==================================================
Accept connection? (y/n): y
Establishing secure connection...
Secure connection established!
==================================================
  You can now chat securely. Type 'exit' to quit.
==================================================

Custom Port

echat -p 8888

How It Works

┌─────────────┐                    ┌─────────────┐
│   User A    │                    │   User B    │
│             │                    │             │
│  Listening  │   Connection Req   │  Listening  │
│  on :9999   │◄───────────────────│  on :9999   │
│             │                    │             │
│             │   Accept? (y/n)    │             │
│             │──────────────────►│             │
│             │                    │             │
│             │   Key Exchange     │             │
│             │◄──────────────────►│             │
│             │                    │             │
│             │  Encrypted Chat    │             │
│             │◄══════════════════►│             │
└─────────────┘                    └─────────────┘

1. Both users start echat - Each listens for incoming connections
2. One user connects - Enters the other's IP address
3. Accept/Reject - Receiver chooses to accept or reject
4. Key Exchange - Diffie-Hellman establishes shared secret
5. Secure Chat - All messages encrypted with AES-256

Security

• ✅ Private keys never leave each machine
• ✅ Shared secret computed independently on both sides
• ✅ All messages encrypted with AES-256
• ✅ Each session generates new keys
• ✅ No central server - direct peer connection

Requirements

• Python 3.8+
• cryptography library

Contributing

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