Quantum-Classical Hybrid Encryption Framework Based on Simulated BB84 and AES-256: Design and Experimental Evaluation

This paper presents the design, implementation, and evaluation of a hybrid encryption framework that combines quantum key distribution, specifically a simulated BB84 protocol, with AES-256 encryption. The system enables secure file encryption by leveraging quantum principles for key generation and classical cryptography for data protection. It introduces integrity validation mechanisms, including HMAC verification and optional post-quantum digital signatures, ensuring robustness even in the presence of quantum-capable adversaries. The entire architecture is implemented in Python, with modular components simulating quantum key exchange, encryption, and secure packaging. Experimental results include visual testing of various attack scenarios, such as key tampering, HMAC failure, and file corruption, demonstrating the effectiveness and resilience of the approach. The proposed solution serves as a practical foundation for quantum-aware cybersecurity systems.