🛡️ PQChatSecure

A lightweight JavaScript library for secure message encryption using Post-Quantum Cryptography (PQC) + Classical Cryptography. Designed to simulate the cryptographic core of a future-proof messaging application that remains secure even in the age of quantum computing.

✨ Features

• 🔐 Hybrid Key Exchange using:
  • Kyber-768 (Post-Quantum Secure)
  • X25519 (Classical ECC)
• 🧠 SHA-256 Hashing for secure shared key derivation
• 📡 One-time Prekeys for asynchronous key exchanges (like Signal)
• 🔒 Authenticated Encryption with NaCl's SecretBox (XSalsa20 + Poly1305)
• 📊 Benchmark Tool to compare PQ performance with classical approaches

🧪 How It Works

1. Identity Key Generation
   Each user generates a hybrid key (Kyber + X25519).

2. Prekey Creation
   A user generates one-time-use prekeys to be shared with others.

3. Hybrid Key Exchange
   One user uses a prekey to derive a shared symmetric key via:

   • Kyber KEM (quantum-safe)
   • X25519 ECDH (classical)
   • Combined using SHA-256

4. Message Encryption & Decryption
   Messages are encrypted using NaCl’s secretbox() and securely decrypted.

🚀 Quick Start