A Review on the Advances, Applications, and Future Prospects of Post-Quantum Cryptography in Blockchain and IoT

With the advancement of quantum computing, classical public-key cryptosystems are increasingly vulnerable, prompting global standardization efforts by organizations such as NIST, ETSI, and ISO. This paper presents a comprehensive review of recent advancements in post-quantum cryptography (PQC), with a particular focus on lattice-based, hash-based, and multivariate approaches. The study examines the security foundations, implementation challenges, and the applicability of these approaches across various domains, including finance, blockchain, and the Internet of Things (IoT). A key contribution of this work is the proposed Hybrid Cryptographic Framework (HCF), which integrates classical and quantum-resistant primitives, facilitating a secure and interoperable transition. This framework combines hybrid key exchange mechanisms, dual-signature schemes, and PQC-compatible Merkle trees, supported by a discrete multi-objective optimization model to select algorithms that meet real-world constraints. The paper also addresses deployment challenges, such as hardware acceleration, side-channel resistance, and legacy system compatibility. Real-world case studies demonstrate how leading institutions are actively piloting PQC integration. Finally, we present a strategic roadmap for the adoption of PQC, incorporating adaptive triggers based on quantum capabilities and evolving threat models. By aligning cryptographic design with international standards and practical system requirements, this paper provides valuable guidance for constructing resilient, quantum-safe infrastructures.