Post-quantum AES encryption using ECC points derived from BB84 sifted keys

Generating a secure key and securely communicating it are crucial aspects for ensuring information security during encryption and decryption processes. Quantum Key Distribution (QKD) is a promising technique for enabling secure communication in Industrial Internet of Things (IIoT) applications. This paper presents an enhanced BB84 protocol integrated with Elliptic Curve Cryptography (ECC) that improves efficiency, security, and practical implementation. Our enhanced BB84 protocol employs a basis reconciliation mechanism and introduces a depolarizing channel model to simulate realistic noise conditions and eavesdropping detections. The system effectively identifies potential eavesdroppers based on Quantum Bit Error Rate (QBER) thresholds, thereby ensuring a secure key exchange process. Unlike traditional ECC implementations, our approach dynamically extracts prime numbers from a sifted key to generate elliptic curve parameters. The extracted key is used for AES encryption, providing an additional security layer for data confidentiality. The performance evaluation demonstrates efficient key generation and computational time, making this approach practical for IIoT environments. The experimental results indicate successful key generation and privacy amplification with a final key derived from the matched measurement bases. Elliptic curve generation successfully computes valid points supporting secure cryptographic operations. The estimated QBER ranged from 0.0 to 0.25, ensuring a secure key exchange. The AES encryption and decryption processes validate the usability of the generated key in real-world applications, confirming the robustness of our integrated QKD-ECC framework. The average key generation time ranged from 0.0000297 s, while the computational time was 0.0000714 s.