Evaluating the Impact of Quantum Algorithms on Modern Cybersecurity Mechanisms

Abstract—The emergence of quantum computing represents a fundamental challenge to contemporary cryptographic infras- tructures, mandating immediate adoption of quantum-resistant cryptographic standards to ensure long-term security. This paper analyzes how Shor’s algorithm renders RSA , ECC vulnerable by solving integer factorization and discrete alogarithm problems in polynomial time, while Grover’s algorithm weakens symmetric encryption through quadratic speedup attacks. Through compre- hensive cryptanalysis, we evaluate the vulnerabilities of current public-key infrastructures, symmetric ciphers, and hash functions against quantum threats. Our research systematically examines post-quantum cryptographic candidates, including lattice-based, hash-based, and multivariate polynomial schemes under NIST standardization, assessing their security guarantees and imple- mentation challenges. Furthermore, we investigate the broader implications for secure communications, blockchain networks, and authentication protocols in a post-quantum world. Based on our findings, we propose a practical transition framework featuring hybrid cryptographic systems, protocol enhancements, and policy updates to facilitate seamless migration. This work provides critical insights and actionable strategies for securing digital infrastructure against quantum threats while maintaining operational efficiency during the transition period. Index Terms—Cryptographic vulnerability, Grover’s algo- rithm, Post-quantum cryptography, Quantum computing, Quan- tum key distribution, Shor’s algorithm, Cybersecurity