Evaluating Post-Quantum Cryptography in the Era of Quantum Supremacy: Quantum Shadows

Abstract

As the era of quantum supremacy emerges, traditional public-key cryptographic schemes such as RSA and ECC face obsolescence due to their vulnerability to Shor’s algorithm, which can efficiently solve integer factorization and discrete logarithm problems. This imminent threat has prompted a global shift toward post-quantum cryptography (PQC)—cryptographic algorithms believed to be secure against both classical and quantum adversaries. This paper presents a critical evaluation of leading PQC candidates, including lattice-based, code-based, multivariate polynomial, and hash-based cryptosystems, with a focus on their security guarantees, computational efficiency, and implementation feasibility. By simulating quantum attacks and benchmarking algorithmic performance across multiple platforms, we explore how these schemes hold up under realistic constraints of quantum hardware and classical integration. We also assess the implications of the NIST standardization process and analyze potential vulnerabilities arising from side-channel and hybrid quantum-classical attacks. Our findings highlight the practical trade-offs between security and performance, identifying the most resilient PQC candidates for various application domains, from IoT devices to enterprise-level communications. As we stand in the shadow of quantum computing’s full realization, this study aims to guide the cryptographic transition toward a more secure, quantum-resilient future.