Quantumcryptlib

QuantumCryptLib is a Rust library for building post-quantum secure communication channels using Kyber512 (a NIST-selected post-quantum Key Encapsulation Mechanism) combined with modern AEAD encryption.

Rather than encrypting data directly with Kyber, this library follows industry-correct cryptographic design:

Kyber KEM → Shared Secret → AEAD (ChaCha20-Poly1305)

This approach protects today’s communications and stored data against future quantum attacks (“harvest now, decrypt later”).

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Key Capabilities

• Post-quantum key establishment using Kyber512 (KEM)
• Shared secret derivation for secure sessions
• Authenticated encryption via ChaCha20-Poly1305
• Fully tested secure channel handshake
• Written in Rust 2021 for safety and performance

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Cryptographic Model (Important)

Kyber512 is a Key Encapsulation Mechanism (KEM) — it is not used to encrypt application data directly.

QuantumCryptLib implements the recommended construction:

1. Key Encapsulation (Kyber512)
   Establishes a shared secret between two parties
2. Key Derivation
   Derives a symmetric encryption key from the shared secret
3. AEAD Encryption (ChaCha20-Poly1305)
   Encrypts and authenticates application data

This model is used in:

• Post-quantum TLS / mTLS
• Zero-Trust service-to-service communication
• Secure tunnels and long-term data protection

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Real-World Use Cases

• Post-Quantum Secure Channels (TLS / mTLS alternatives)
• Zero-Trust Microservices Communication
• Long-Term Data Protection & Archival Encryption
• Financial, Government, and Critical Infrastructure Systems
• Blockchain & Distributed System Secure Messaging

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Installation

️⃣ Clone the repository:

git clone https://github.com/0rlych1kk4/quantumcryptlib.git
cd quantumcryptlib

Build project:

cargo build
cargo run --bin quantumcryptlib_bin

Usage

Generating Kyber Key Pair

use quantumcryptlib::key_exchange::generate_key_pair;

let (public_key, secret_key) = generate_key_pair();

Establish a Post-Quantum Shared Secret (KEM)

use quantumcryptlib::key_exchange::{encapsulate, decapsulate};

// Initiator
let (shared_secret_a, kem_ciphertext) = encapsulate(&public_key)?;

// Responder
let shared_secret_b = decapsulate(&secret_key, &kem_ciphertext)?;

assert_eq!(shared_secret_a, shared_secret_b);

 **Encrypt and Decrypt Data Using AEAD**
use quantumcryptlib::secure_channel::{aead_encrypt, aead_decrypt};

let message = b"hello post-quantum world";

// Encrypt
let (nonce, ciphertext) = aead_encrypt(&shared_secret_a, message)?;

// Decrypt
let plaintext = aead_decrypt(&shared_secret_b, &nonce, &ciphertext)?;

assert_eq!(message.to_vec(), plaintext);

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Testing

Integration tests validate the following:

• Multiple independent KEM handshakes
• Shared secret correctness
• AEAD encryption and decryption cycles

Run tests

cargo test

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Security Notes

• Secrets are never printed
• AEAD ensures confidentiality and authenticity
• Kyber512 is NIST-selected for post-quantum key exchange
• This library is a secure communication building block, not a full TLS replacement

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Planned Hardening

• HKDF
• Hybrid classical + post-quantum key exchange
• Secret zeroization
• no_std support

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Contributing

1. Fork the repository
2. Create a feature branch

   git checkout -b feature-branch
   

3. Commit your changes

   git commit -m "Add feature"
   

4. Push and open a pull request

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