The Impact of Quantum Computing on Cryptographic Systems: Urgency of Quantum-Resistant Algorithms and Practical Applications in Cryptography

Quantum computing presents computational powers previously thought unattainable. This brings severe threats to classical cryptographic methods, especially RSA and ECC. This paper addresses these risks through a detailed investigation of quantum-resistant algorithms, focusing on lattice- based (CRYSTALS-Kyber), hash-based (SPHINCS+), and code-based (McEliece) systems. Research questions guiding this study include: How vulnerable are traditional algorithms under quantum attack, and which quantum-resistant alternatives offer viable performance and security trade-offs? Through simulations, we analyzed key metrics like encryption speeds, key sizes, and efficiency under quantum threats. Additionally, we demonstrated vulnerabilities in RSA-2048 and ECC-256 under Shor’s algorithm, emphasizing the necessity for quantum-resistant cryptography. Our results highlighted CRYSTALS-Kyber as a balanced candidate, aligning with the NIST PQC Standardization, while Quantum Key Distribution (QKD) is reviewed for high-sensitivity contexts. Given the forecasted advancements in quantum hardware, we propose a transitional approach using hybrid cryptographic systems to ensure immediate security and ease the shift to quantum-safe protocols. This study also explores industry applications, particularly in finance, healthcare, and IoT, recommending a phased adoption strategy utilizing hybrid cryptographic systems for a secure, gradual transition.