The rise of quantum computing presents a critical threat to classical public-key cryptographic systems, necessitating a global shift toward post-quantum cryptography (PQC). While algorithmic standardisation has seen substantial progress since the National Institute of Standards and Technology (NIST) initiated its call for PQC proposals in 2017, the integration of these algorithms into certificate-based infrastructures remains fragmented and underexplored. This gap creates uncertainty for secure communication, particularly in transitioning legacy systems into quantum-resilient environments. This systematic literature review (SLR) focuses on PQC certificate architectures studied between 2017 and 2025, encompassing the evolution of the field since NIST's formal standardisation efforts began. The review employs the PRISMA 2020 methodology to identify and analyse six distinct post-quantum certificate models: Pure PQC, Hybrid, Composite, Chameleon, Parallel, and Wrapped. Each model is evaluated across several criteria, including structure, backwards compatibility, tooling support, standardisation status, and production readiness, drawing evidence from scholarly publications, draft standards, and open-source implementations. Findings highlight the Hybrid certificate as the most viable short-term solution due to its high interoperability and maturity in deployment. Composite and Parallel architectures offer enhanced security assurances that are suitable for critical infrastructure, although they come with increased implementation complexity. Pure PQC certificates, while future-proof, are still limited to constrained or greenfield environments. Chameleon and Wrapped models are identified as emerging alternatives for blockchain and legacy scenarios, respectively, with limited but growing support. This review enlightens the design and deployment of quantum-safe public key infrastructures by outlining the trade-offs and maturity levels of each architecture. It also emphasises the need for continued development in standardisation and toolchain support to facilitate scalable and secure PQC adoption.
The rise of quantum computing presents a critical threat to classical public-key cryptographic systems, necessitating a global shift toward post-quantum cryptography (PQC). While algorithmic standardisation has seen substantial progress since the National Institute of Standards and Technology (NIST) initiated its call for PQC proposals in 2017, the integration of these algorithms into certificate-based infrastructures remains fragmented and underexplored. This gap creates uncertainty for secure communication, particularly in transitioning legacy systems into quantum-resilient environments. This systematic literature review (SLR) focuses on PQC certificate architectures studied between 2017 and 2025, encompassing the evolution of the field since NIST's formal standardisation efforts began. The review employs the PRISMA 2020 methodology to identify and analyse six distinct post-quantum certificate models: Pure PQC, Hybrid, Composite, Chameleon, Parallel, and Wrapped. Each model is evaluated across several criteria, including structure, backwards compatibility, tooling support, standardisation status, and production readiness, drawing evidence from scholarly publications, draft standards, and open-source implementations. Findings highlight the Hybrid certificate as the most viable short-term solution due to its high interoperability and maturity in deployment. Composite and Parallel architectures offer enhanced security assurances that are suitable for critical infrastructure, although they come with increased implementation complexity. Pure PQC certificates, while future-proof, are still limited to constrained or greenfield environments. Chameleon and Wrapped models are identified as emerging alternatives for blockchain and legacy scenarios, respectively, with limited but growing support. This review enlightens the design and deployment of quantum-safe public key infrastructures by outlining the trade-offs and maturity levels of each architecture. It also emphasises the need for continued development in standardisation and toolchain support to facilitate scalable and secure PQC adoption.
Purpose: The purpose of this paper is to examine the emerging threat that large-scale quantum computing poses to classical public-key cryptographic systems, particularly RSA and Elliptic Curve Cryptography (ECC), which form the backbone of contemporary digital security infrastructures. In response to this threat, the study aims to analyze post-quantum cryptography (PQC) as a viable long-term solution capable of resisting both classical and quantum adversaries. The paper further seeks to assess the urgency of PQC adoption in light of the “harvest now, decrypt later” threat model and to evaluate the practical readiness of quantum-safe cryptographic algorithms currently under consideration by the National Institute of Standards and Technology (NIST). Materials and Methods: This study employs a qualitative and analytical research methodology grounded in an extensive review of authoritative sources, including NIST’s post-quantum cryptography standardization documents, recent academic literature, industry white papers, and policy reports from organizations such as RAND Corporation and Cloudflare. The analysis systematically surveys major families of post-quantum cryptographic algorithms namely lattice-based, code-based, and hash-based schemes and evaluates them based on security assumptions, computational efficiency, implementation complexity, and standardization maturity. Findings: The analysis indicates that Lattice-based cryptographic schemes demonstrate the highest maturity and practical readiness, evidenced by their selection in NIST’s PQC process. Code- and hash-based methods provide strong security but face key size and performance challenges. The lack of scalable quantum computers does not reduce urgency, as data harvesting persists. Artificial intelligence emerges as a key enabler for accelerating PQC adoption. Unique Contribution to Theory, Practice and Policy: The paper recommends a proactive, phased post-quantum migration using hybrid cryptographic architectures. Organizations should conduct inventories, benchmarking, and pilot deployments aligned with NIST standards. AI-driven tools are advised to improve key management and reduce complexity. Continued interdisciplinary research and policy support are encouraged to ensure a secure, scalable transition to quantum-resistant security systems.
Development of Quantum Computers are growing rapidly, the security of today’s cryptographic systems which are working with Public Key Infrastructure (PKI) is at serious risk. RSA and ECC algorithms are the backbone of secure communication and digital identity can be breakable by quantum algorithms such as Shor’s. Hence, a transition is required to Post-Quantum Cryptography (PQC), which is designed to handle quantum attacks. This work provides a detailed review of how PQC can be integrated with the existing PKI, with a special focus on the auto-enrollment process. Auto-enrollment is an essential process but often overlooked mechanism, responsible for automatically issuing and renewing digital certificates. First, we explored how current PKI systems are exposed to the quantum threats and the readiness. The performance of the algorithms that are standardized by NIST, such as Kyber and Dilithium were discussed. We analyze the technical and operational challenges of transitioning to PQC by referencing both research studies and real-world implementations from major industry players such as Google and Microsoft. These include large key size, certificate size, compatibility issues, complex computations and need for crypto-agility. We also examine the hybrid approaches that combine classical and post-quantum methods as traditional strategies. The survey concludes by outlining best practices, deployment considerations, and open research challenges that must be addressed for a smooth, secure, and scalable shift to quantum-safe PKI. This work aims to guide researchers, engineers, and policymakers in building the next generation of cryptographic infrastructure that can stand the test-time even in a quantum world.
The advent of quantum computing poses a significant threat to current cryptographic systems, particularly public-key algorithms such as RSA and ECC, which are vulnerable to quantum attacks like Shor's algorithm. Post-Quantum Cryptography (PQC) aims to develop and standardize quantum-resistant cryptographic algorithms to secure digital communications in the quantum era. This paper examines the current landscape of PQC, focusing on the evaluation and standardization efforts led by organizations such as the National Institute of Standards and Technology (NIST). We analyze the major families of quantum-resistant algorithms, including lattice-based, hash-based, code-based, multivariate, and isogeny-based cryptography, discussing their security guarantees, performance trade-offs, and implementation challenges. Furthermore, we review NIST's PQC standardization process, highlighting selected finalists and alternate candidates, and explore the ongoing transition challenges in adopting these algorithms across industries. Finally, we discuss future directions for PQC research, including hybrid cryptographic systems and the need for continued cryptanalysis to ensure long-term security. This work provides a comprehensive overview of the progress and challenges in deploying quantum-resistant cryptography to safeguard against emerging quantum threats.
The conventional cryptographic systems that underpin the world's financial infrastructure are under grave threat as quantum computing spreads. The financial industry must immediately investigate quantum-safe alternatives, as widely used public-key algorithms such as RSA and Elliptic Curve Cryptography (ECC) are theoretically susceptible to Shor's quantum algorithm, while symmetric schemes face reduced security margins under Grover's algorithm. The Systematic Literature Review (SLR) presented in this paper was carried out in compliance with PRISMA 2020 guidelines. Web of Science, Scopus, and Google Scholar were searched using Boolean keywords to find articles published between 2013 and 2025. 53 high-quality studies were chosen from an original corpus of N = 1,654 publications utilizing the Mixed Methods Appraisal Tool (MMAT), systematic screening, and eligibility evaluation. Three main paradigms for quantum cryptography were found: Post-Quantum Cryptography (PQC), which includes the NIST-standardised lattice-based algorithms CRYSTALS-Kyber and CRYSTALS-Dilithium (NIST, 2022); Quantum Key Distribution (QKD), which offers information-theoretic security through the BB84, E91, and CV-QKD protocols; and hybrid quantum-classical architectures that combine near-term deployment with long-term quantum resilience. The operational viability of quantum-secure financial communication has been confirmed through real-world deployments by JPMorgan Chase, HSBC, CaixaBank, and Danske Bank. Given the 'harvest now, decrypt later' (HNDL) threat paradigm, the evidence clearly shows that upgrading to quantum-safe cryptography is an essential operational necessity. Complementary approaches with different trade-offs in cost, scalability, and implementation maturity include QKD, PQC, and hybrid frameworks. To protect the integrity of international financial systems, financial regulators and institutions must coordinate faster adoption roadmaps aligned with NIST PQC standardisation timelines.
The threats are existential to the traditional cryptosystems of public keys, including RSA, Diffie-Hellman, and elliptic curve cryptography (ECC), due to the rapid progress in quantum computing. Such algorithms as the Shor and Grover algorithms prove that as soon as large scale quantum computers are achieved, these classical cryptographic protocols will not provide any privacy and integrity to online communication. This has created an emergency to find post-quantum cryptography (PQC), or quantum-safe cryptography, which will resist attacks by both classical and quantum attackers. The paper is a review of the latest research and development in post-quantum cryptographic algorithms and their implementation in current security systems. We organize quantum-safe methods into significant organizations such as lattice-based, hash-based, multivariate polynomial-based and code-based encrypted communications. Each type has been evaluated critically based on computational efficiency, key sizes, speed of encryption/decryption and security proofs. The survey also examines the current standardization activities happening in the world and especially the U.S. National Institute of Standards and Technology (NIST) PQC competition, which lists candidate algorithms that have advanced to standard adoption. Besides this, the paper addresses hybrid cryptographic designs that use both classical and post-quantum bases in ensuring a seamless migration in the transition phase. Internet security protocols like TLS, VPNs and blockchain consensus as applications of PQC are examined in detail. Lastly, we pinpoint open research issues, which include creating lightweight PQC to support resource-constrained IoT devices, balancing performance and strong security assurances, and interoperability between the new PQC algorithms and existing infrastructures. Through detailed survey we inform the future of researchers, practitioners, and policymakers on the preparation of the post-quantum era of secure digital communications.
The prospect of a cryptographically relevant quantum computer (CRQC) undermines the public-key primitives that secure virtually every layer of modern communication networks, from subscriber authentication in cellular cores to transport-layer key exchange. Adversaries already following a harvest-now, decrypt-later (HNDL) strategy make this threat actionable today for any traffic whose confidentiality must outlast a decade. Following NIST’s finalisation of the first post-quantum cryptography (PQC) standards, ML-KEM (FIPS 203), ML-DSA (FIPS 204), and SLH-DSA (FIPS 205) in August 2024, and the selection of HQC as a fourth key-encapsulation candidate in March 2025, research has shifted from algorithm design to network-level integration. This paper reports a PRISMA-2020-compliant systematic literature review of PQC migration in communication networks, structured around five research questions covering protocol and scenario coverage, quantitative performance impact, hybrid cryptography strategies, transition barriers, and open research gaps. Six databases (IEEE Xplore, Scopus, Web of Science, ACM Digital Library, SpringerLink, and MDPI) were searched (3229 records identified); after deduplication, title-keyword screening, full-text eligibility assessment, and a pre-specified quality appraisal (Q1–Q6, threshold ≥3/6) applied to 310 eligible studies, a final synthesis corpus of 141 studies (68 journal articles, 68 conference papers, 4 conference-derived book chapters, 1 workshop paper) was screened, quality-appraised, and synthesised narratively with supporting evidence tables. The review finds that transport-layer protocols (TLS 1.3, QUIC, DTLS 1.3) dominate the literature, that lattice-based ML-KEM/ML-DSA offer the most favourable latency–bandwidth–energy trade-off among standardised families, and that classical–PQC hybrid schemes are the de facto transition strategy across 5G/6G, IoT, VPN, and automotive scenarios, at the cost of 10–100× larger keys/signatures and 8–40% handshake latency overhead. Persistent barriers include constrained-device resource limits, immature hardware acceleration, incomplete IETF/3GPP standardisation, and public-key-infrastructure scaling. We propose a five-level PQC transition-readiness maturity model and identify large-scale field validation, PQC–QKD integration, and lightweight signature schemes as priority directions for future work.