Securing the Future: A Comprehensive Review of Post-Quantum Cryptography in the Modern Threat Landscape

Abstract

The accelerating development of quantum computing represents one of the most significant paradigm shifts in the history of information security. Cryptographic systems that currently underpin global digital infrastructure—including RSA, Diffie–Hellman, and Elliptic Curve Cryptography—rely on mathematical assumptions that collapse under quantum algorithms such as Shor’s and Grover’s. Post-Quantum Cryptography (PQC) emerges as the most viable and immediate solution to secure communications in the quantum era, offering cryptographic primitives that can be deployed on today’s classical hardware while resisting both classical and quantum attacks. This review provides a comprehensive, detailed examination of PQC, analyzing its mathematical foundations, algorithmic families, standardization progress, and deployment challenges. Special emphasis is placed on the NIST PQC standardization process, the risk posed by “harvest-now-decrypt-later” adversaries, the complexities of global cryptographic migration, and the implications for critical digital infrastructures such as cloud computing, blockchain systems, long-lifespan data archives, IoT ecosystems, and national cybersecurity. Through standalone equations, tables, and figures—including a conceptual visual provided by the user—this paper offers a complete, cohesive, and rigorous synthesis. The findings underscore that the transition to PQC is not optional but imperative, requiring coordinated scientific, governmental, and industrial effort to safeguard the digital future.