CrypTon: A Hybrid Quantum-Classical Framework Integrating BB84 QKD with AES for Secure Communication

Overview

Quantum computers are coming for classical encryption. CrypTon is an IEEE-published research framework that integrates Quantum Key Distribution (BB84 protocol) with AES encryption to build a hybrid cryptographic system that is secure against quantum attacks, without modifying the cipher itself. Implemented in Qiskit and Python, the system achieved 97.3% eavesdropper detection accuracy across 1000 trials, proving that quantum-secured keys can be seamlessly plugged into existing AES infrastructure.

About This Research

Classical encryption like AES is fast, battle-tested, and deployed everywhere, but its long-term security depends entirely on one thing: the secrecy of the key. As quantum computers become more capable, algorithms like Shor's and Grover's can break the mathematical assumptions that classical key exchange relies on.

CrypTon answers this with a hybrid approach. Instead of replacing AES, it replaces how the key is generated and distributed, using the BB84 Quantum Key Distribution protocol, where the laws of quantum physics guarantee that any eavesdropping attempt is detectable.

The system was built and benchmarked in Qiskit (IBM's quantum computing framework) across three key sizes (128, 192, 256 bits) and three file sizes (10 KB, 100 KB, 1 MB). Key findings:

— AES encryption throughput (250–370 MB/s) was completely unaffected by whether keys came from a quantum or classical source. The cipher doesn't care where the key came from.

— Quantum key generation via BB84 takes 38–111 seconds depending on key size, significantly slower than classical PRNG, but this cost is amortized in practice by running QKD continuously in the background and maintaining a key buffer.

— Eavesdropper detection achieved 97.3% accuracy across 1000 trials. When an interceptor (Eve) was present, Quantum Bit Error Rate (QBER) spiked to 20–30%, triggering automatic key rejection. Zero false positives were recorded.

The conclusion is clear: classical and quantum cryptography are not competitors, they are complements. CrypTon demonstrates a practical path to quantum-safe communication that enterprises can adopt without overhauling their existing AES infrastructure.

Published at the 2026 International Conference on Next-Gen Quantum and Advanced Computing (NQComp), IEEE.