Demystifying Cryptography: An Experimental Study of Classical and Quantum Cryptography

Quantum computers are on the brink of becoming a reality, offering revolutionary advancements in various fields such as material science, pharmaceuticals, artificial intelligence, and fundamental science. However, they simultaneously pose a significant threat to conventional cryptographic systems, particularly RSA, which are susceptible to quantum attacks. This study critically examines the imminent risks that quantum computing presents to cryptography, emphasizing the necessity for immediate evaluation and contextualization. Three experiments were conducted. Experiment 1 evaluated the security resilience of RSA algorithms by estimating the decryption time for both classical and quantum computers. The findings revealed a stark contrast, approximately 3.84×10²⁷ years for classical computers versus roughly 8 hours for quantum computers based on an MIT study. Experiment 2 involved a comparative analysis of RSA and ECC across seven distinct criteria, using a fixed-size file to record key generation, encryption, and decryption times. Results indicated ECC's superiority, demonstrating enhanced efficiency, smaller key sizes, and faster operational times compared to RSA. Experiment 3 focused on the efficacy of classical Diffie-Hellman key exchange protocol versus two quantum key distribution protocols, BB84 and E91, under a man-in-the-middle attack scenario. The outcomes highlighted Diffie-Hellman's lack of user authentication, while BB84 and E91 successfully detected tampering through their physics-based cryptographic properties. The research underscores higher security offered by physics-based cryptographic methods over traditional math-based protocols. This comprehensive analysis elucidates the tangible threats posed by quantum computing and proposes viable solutions for enhancing cryptographic security in the quantum era.