A Systematic Review of Graph-Theoretic Approaches to Post-Quantum Cryptographic Protocols: Methods, Architectures, and Future Research Directions

Abstract

The rapid advancement of quantum computing poses a significant threat to classical cryptographic systems, necessitating the development of robust post-quantum cryptographic (PQC) protocols. Among emerging approaches, graph-theoretic techniques have gained prominence due to their computational hardness, structural flexibility, and applicability in designing secure cryptographic primitives. This paper presents a systematic review of graph-theoretic approaches to post-quantum cryptographic protocols, focusing on methods, architectures, and future research directions. The study analyzes recent developments from 2018 to 2025, examining how graph-based constructs such as expander graphs, isogeny graphs, lattice graphs, and combinatorial structures contribute to secure key exchange, encryption, and authentication mechanisms. Additionally, the integration of chaotic systems and generative artificial intelligence is explored to enhance entropy generation and adaptive security mechanisms. The review identifies key trends, including hybrid graph-chaotic models, optimization of graph traversal algorithms for cryptographic efficiency, and AI-assisted cryptanalysis resistance. Contributions of this work include a structured synthesis of 30 studies, identification of research gaps in scalability and standardization, and a comprehensive evaluation of graph-theoretic PQC within secure software engineering frameworks. The findings emphasize the potential of graph-based cryptography as a resilient paradigm in the quantum era while highlighting the need for further interdisciplinary research.