Abstract Quantum computing threatens the public-key cryptography on which contemporary digital infrastructure depends, and the practical question has shifted from whether that threat will materialise to how quickly organisations are obliged to respond. Two developments drove this shift: the United States National Institute of Standards and Technology published its first post-quantum cryptographic standards in August 2024, and in June 2026 an executive order attached binding dates to their adoption across federal systems and federal contractors. This review examines those developments through targeted retrieval of primary standards and policy documents, together with peer-reviewed cryptanalytic and resource-estimation literature, with bibliographic details verified against publisher records. Three principal findings emerge. First, the standardised portfolio is smaller than commonly reported: three Federal Information Processing Standards are published, a fourth remains in development, and a fifth algorithm has been selected but not yet standardised, a distinction that matters because procurement obligations attach only to published standards. Second, two candidates that reached advanced evaluation were defeated by classical rather than quantum cryptanalysis, one within a weekend on consumer hardware. Third, published estimates of the quantum resources required to break widely deployed key sizes have moved by more than an order of magnitude in a single dimension within six years, exchanging machine size for running time. The review concludes that cryptographic agility, not the selection of any particular algorithm, is the durable objective, and that migration should be prioritised by the confidentiality lifetime of data rather than by forecasts of adversary capability. Keywords: Standardization; Keywords: post-quantum cryptography; cryptographic migration; cryptographic agility; critical infrastructure
Abstract Quantum computing threatens the public-key cryptography on which contemporary digital infrastructure depends, and the practical question has shifted from whether that threat will materialise to how quickly organisations are obliged to respond. Two developments drove this shift: the United States National Institute of Standards and Technology published its first post-quantum cryptographic standards in August 2024, and in June 2026 an executive order attached binding dates to their adoption across federal systems and federal contractors. This review examines those developments through targeted retrieval of primary standards and policy documents, together with peer-reviewed cryptanalytic and resource-estimation literature, with bibliographic details verified against publisher records. Three principal findings emerge. First, the standardised portfolio is smaller than commonly reported: three Federal Information Processing Standards are published, a fourth remains in development, and a fifth algorithm has been selected but not yet standardised, a distinction that matters because procurement obligations attach only to published standards. Second, two candidates that reached advanced evaluation were defeated by classical rather than quantum cryptanalysis, one within a weekend on consumer hardware. Third, published estimates of the quantum resources required to break widely deployed key sizes have moved by more than an order of magnitude in a single dimension within six years, exchanging machine size for running time. The review concludes that cryptographic agility, not the selection of any particular algorithm, is the durable objective, and that migration should be prioritised by the confidentiality lifetime of data rather than by forecasts of adversary capability. Keywords: Standardization; Keywords: post-quantum cryptography; cryptographic migration; cryptographic agility; critical infrastructure
The emergence of cryptographically relevant quantum computing presents a strategic governance challenge for national security because contemporary digital infrastructures depend extensively on public-key cryptographic mechanisms whose long-term security may be threatened by sufficiently capable quantum computers. This research examines post-quantum cryptographic governance as a policy, risk-management, interoperability, and implementation problem rather than solely as a cryptographic algorithm-selection exercise. The study adopts a conceptual research-and-review methodology based exclusively on the supplied literature, using insights from security and privacy, interoperability, digital transformation, standards-based architectures, and emerging technology governance to construct an integrated post-quantum governance framework. Particular attention is given to cryptographic inventory, risk prioritization, migration governance, interoperability, institutional accountability, lifecycle management, and national-security continuity. The analysis indicates that post-quantum readiness requires coordinated governance across technical and organizational layers, with migration decisions guided by asset criticality, data longevity, dependency relationships, and operational constraints. The study further argues that interoperability principles are central to post-quantum migration because cryptographic transitions must coexist with heterogeneous legacy systems and distributed information environments. The proposed framework therefore combines risk assessment, policy development, technical migration, validation, monitoring, and institutional oversight. The research contributes a governance-oriented perspective in which cryptographic agility and standards-based interoperability become strategic national-security capabilities rather than isolated technical controls.
The prospect of cryptographically relevant quantum computers threatens public-key primitives underpinning modern digital infrastructure, including RSA, Diffie-Hellman, and elliptic-curve cryptography. Post-quantum cryptography (PQC) responds with algorithms believed to be hard for both classical and quantum adversaries. In August 2024, the U.S. National Institute of Standards and Technology (NIST) finalised the first three PQC standards: FIPS 203 (ML-KEM, based on Kyber), FIPS 204 (ML-DSA, based on Dilithium), and FIPS 205 (SLH-DSA, based on SPHINCS+). This paper surveys the algorithmic families behind these standards, the harvest-now-decrypt-later threat model, hybrid migration strategies, performance trade-offs, and the engineering challenges of transitioning the global cryptographic stack. We examine deployment progress in TLS, SSH, X.509, and constrained devices, and outline open research questions on side-channel security, falcon-style signatures, and the long-term replacement schedule for classical asymmetric cryptography.
The impressively fast development of quantum computing is a serious threat to classical public-key cryptography, and algorithms such as Shor's and Grover's will render RSA and elliptic curve systems essentially useless as soon as a cryptanalytically relevant quantum computer becomes available. Although it is still some way off before such machines are available, the harvest-now-encrypt-later threat highlights the need for proactive defense. In response, the National Institute of Standards and Technology (NIST) published the first post-quantum cryptography standards in 2024, including ML-KEM (Kyber) for key establishment, ML-DSA (Dilithium) for digital signatures and SLH-DSA (SPHINCS+) as a stateless hash-based alternative. This paper is a summary of the evolving post-quantum landscape, starting with the standards and their underlying security and then moving on to migration policies such as CNSA 2.0 and CISA, NSA and NIST guidance. It also looks at integration patterns for important protocols such as TLS, IPsec, SSH, and code signing. A performance, interoperability and overhead evaluation methodology is presented with results showing that hybrid deployment and crypto-agile architectures make PQC adoption a viable option. The paper concludes by providing a governance-oriented roadmap, where inventory, prioritization and pilot deployments are identified as near-term actions, with open questions remaining on performance optimization, implementation security and algorithm resilience over time.
Large-scale quantum computers threaten the public-key cryptography that protects enterprise data, communications, and digital identity. Shor's algorithm solves integer factorization and discrete logarithms in polynomial time, which would break RSA, Diffie-Hellman, and elliptic-curve schemes once a cryptographically relevant quantum computer exists. The danger is not only future. Adversaries can record encrypted traffic today and decrypt it later, a tactic known as harvest-now-decrypt-later. In August 2024 the U.S. National Institute of Standards and Technology published its first post-quantum standards: FIPS 203 (ML-KEM, derived from CRYSTALS-Kyber), FIPS 204 (ML-DSA, from CRYSTALS-Dilithium), and FIPS 205 (SLH-DSA, from SPHINCS+). This paper presents a practical migration framework for enterprises. It reviews the quantum threat and Mosca's inequality for timing the transition, summarizes the new standards with their key and signature sizes, and proposes a five-phase roadmap built on crypto-agility: discovery and inventory, risk prioritization, agility engineering, hybrid deployment, and validation. Performance trade-offs are analyzed using documented parameter sizes and illustrative TLS handshake figures. ML-KEM-768 carries a 1,184-byte public key against 64 bytes for an elliptic-curve key, while SPHINCS+ signatures can exceed 17 kilobytes. The work does not report a real deployment. It consolidates published parameters and field guidance into an actionable plan, and it highlights open challenges in certificate sizing, hardware support, and long-lived embedded systems.
Large-scale quantum computers threaten the public-key cryptography that protects enterprise data, communications, and digital identity. Shor's algorithm solves integer factorization and discrete logarithms in polynomial time, which would break RSA, Diffie-Hellman, and elliptic-curve schemes once a cryptographically relevant quantum computer exists. The danger is not only future. Adversaries can record encrypted traffic today and decrypt it later, a tactic known as harvest-now-decrypt-later. In August 2024 the U.S. National Institute of Standards and Technology published its first post-quantum standards: FIPS 203 (ML-KEM, derived from CRYSTALS-Kyber), FIPS 204 (ML-DSA, from CRYSTALS-Dilithium), and FIPS 205 (SLH-DSA, from SPHINCS+). This paper presents a practical migration framework for enterprises. It reviews the quantum threat and Mosca's inequality for timing the transition, summarizes the new standards with their key and signature sizes, and proposes a five-phase roadmap built on crypto-agility: discovery and inventory, risk prioritization, agility engineering, hybrid deployment, and validation. Performance trade-offs are analyzed using documented parameter sizes and illustrative TLS handshake figures. ML-KEM-768 carries a 1,184-byte public key against 64 bytes for an elliptic-curve key, while SPHINCS+ signatures can exceed 17 kilobytes. The work does not report a real deployment. It consolidates published parameters and field guidance into an actionable plan, and it highlights open challenges in certificate sizing, hardware support, and long-lived embedded systems.
The public-key cryptography that protects government websites, digital signatures, identity services and data exchange would be broken by a large fault-tolerant quantum computer. Although such a machine does not yet exist, sensitive data captured today can be stored and decrypted later, and large government systems take many years to change. Standards bodies have now published the first post-quantum cryptographic algorithms, and security agencies advise organisations to start preparing. This paper proposes a practical, six-stage migration framework for Indian e-government systems: (1) governance and ownership; (2) cryptographic discovery and inventory; (3) risk-based prioritisation using data shelf-life; (4) crypto-agile architecture and procurement; (5) phased migration with hybrid deployment and testing; and (6) assurance and continuous monitoring. It offers a simple prioritisation matrix, a checklist of procurement clauses and a set of readiness indicators that state IT departments and ministries can adopt. The framework is written for public-sector programme managers rather than cryptographers, and focuses on the organisational work that determines whether technical migration succeeds. It is a practitioner framework based on published standards and guidance; it does not evaluate specific products.