Abstract Quantum computing exploits superposition and entanglement to process information in an exponentially large state space, enabling algorithms such as Shor’s to factor large integers efficiently and thereby undermining RSA and elliptic curve cryptography. Quantum cryptography, here encompassing post quantum cryptographic (PQC) algorithms and quantum key distribution (QKD), is a leading candidate for protecting data against quantum capable adversaries. PQC designs classical schemes conjectured to be secure against both quantum and classical attacks, whereas QKD uses quantum mechanics to detect eavesdropping and establish information theoretically secure keys. Existing literature and limitations. Recent surveys summarise PQC families and the standardisation process led by the U.S. National Institute of Standards and Technology (NIST), and reviews outline QKD protocols and their challenges. However, most prior work either addresses narrow subtopics or does not systematically synthesise empirical evidence across technical and application domains. As a result, there is still limited integrated understanding of key issues, technologies, mathematical foun dations, algorithms, programming tools and real world deployments. Objective and contributions of this review. This study systematically analyses 61 peer reviewed journal articles published within the last five years that focus on quantum cryptography. Using Covidence to manage study identification, selection, quality assessment, data extraction and narrative synthesis, it (a) characterises current issues and challenges; (b) surveys recent technological advancements and implementations; (c) evaluates algorithmic approaches and their effectiveness; (d) examines the underlying mathematical models; (e) maps the programming languages and tools used to implement quantum schemes; and (f) synthesises evidence on practical applications and future research directions. The review integrates findings on PQC and QKD, highlights gaps in the current evidence base, and offers practitioners, scholars and policymakers guidance for developing quantum secure communication systems. Keywords Quantum cryptography, Post quantum cryptography, Quantum key distribution, Systematic literature review, Quantum secure communication
Alruwaili et al. (Tue,) studied this question.