The impact on cybersecurityIn the world of quantum computers, the most convincing exponential speedup lies in codebreaking.Anyone who wants to understand the impact of quantum computers must know the basics of cryptography.Let's start at the beginning.The PQC Migration Handbook is a free guide for corporate managers on how to tackle the upcoming cryptography migration, written by dutch research organisations tno, CWI, and the secret service aIvd.In the context of harvest now, decrypt later, the urgency to migrate depends on how long your data should remain confidential, according to mosca's theorem.
The impact on cybersecurityIn the world of quantum computers, the most convincing exponential speedup lies in codebreaking.Anyone who wants to understand the impact of quantum computers must know the basics of cryptography.Let's start at the beginning.The PQC Migration Handbook is a free guide for corporate managers on how to tackle the upcoming cryptography migration, written by dutch research organisations tno, CWI, and the secret service aIvd.In the context of harvest now, decrypt later, the urgency to migrate depends on how long your data should remain confidential, according to mosca's theorem.
This preprint presents a systematic review of how quantum computing impacts the security of classical cryptography and what mitigation strategies are available. The review synthesises key survey papers, standards reports and transition guidelines on post-quantum cryptography (PQC) and quantum-safe security published between 2015 and 2025. First, the paper summarises the impact of Shor’s and Grover’s algorithms on widely deployed public-key schemes, symmetric ciphers and hash functions, highlighting in particular the existential break of RSA, Diffie–Hellman and elliptic-curve cryptography, and the reduced security margins for symmetric and hash-based constructions. It then examines major quantum-resilient responses, including lattice-, code-, multivariate- and hash-based PQC, quantum key distribution (QKD), hybrid classical–PQC schemes and crypto-agile architectures. Building on Mosca’s x, y, z risk-timing model, the review discusses cross-cutting themes such as harvest-now-decrypt-later threats and sector-specific implications for government and defence, finance and blockchain, healthcare, cloud providers and critical infrastructure. It identifies several research gaps, including the lack of quantitative migration-cost data, limited coverage of small and resource-constrained organisations, and few system-scale evaluations comparing PQC-only, hybrid and QKD-based designs. The paper concludes by arguing that planning and investment in quantum-resilient cryptography need to start now, before migration time and data shelf-life push critical systems into the risky regime.
Post-quantum cryptography (PQC) is driven by the threat posed by quantum computers, particularly the harvest-now-decrypt-later attack. PQC aims to prepare classical systems and hardware to become resilient against quantum attacks. This research discusses the system vulnerabilities, the need to migrate to PQC, and how to integrate this migration. PQC has become one of the solutions for addressing today’s vulnerabilities and threats while increasing security. The paper concludes that harvest-now-decrypt-later, Q-Day attacks, and new quantum attacks are today’s most critical threats, which can be addressed by deploying PQC solutions and, thus, increasing security. This research proposes a conceptual multi-phased model framework for the migration. The framework first addresses system objectives, goals and assets, then ranks assets based on the highest sensitivity. Crypto-Agility is achieved via the automation of PQC migration, such as the automation of re-keying endpoints, followed by the automation of auditing and testing of each migration stage. Human judgment is required to review the migration process. Once one asset is successfully transitioned, the framework goes to the next highest asset; otherwise, testing is repeated. This is expected to help systems migrate at the lowest cost and with the fewest consequences. However, the limitation of PQC migration is its high resource cost, time, requirement of human professionals, burden on existing systems, and financial expenses. Lastly, the paper recommends creating an ML model to help rank a system’s data and vulnerabilities. Moreover, the paper recommends conducting experiments to evaluate the effectiveness of the proposed framework. In addition, the paper recommends performing migration in relation to a real-world company.
With the arrival of fault-tolerant quantum computers, an existential threat has come to the cryptographic underpinnings of the security infrastructure in place for modern information technologies. Virtually all secure digital communication protocols used today are based on classical public-key cryptographic systems – RSA, Elliptic Curve Cryptography (ECC) and Diffie-Hellman key exchange – that are susceptible to polynomial-time quantum attacks using Shor's algorithm. Symmetric cryptographic algorithms that are not broken are being effectively halved by Grover's algorithm, for example, AES. In this article, a complete and journal-standard systematic review of quantum computing and its implications in the field of information technology security is presented which includes 22 peer-reviewed publications from 2023-2025. The study covers the basics of quantum computing (qubits, superposition, entanglement and quantum gates), and how quantum computing specifically poses a threat to classical cryptography via algorithmic mechanisms. The three post-quantum cryptographic algorithms that were standardised by the National Institute of Standards and Technology (NIST) in August 2024 (ML-KEM, FIPS 203; ML-DSA, FIPS 204; and SLH-DSA, FIPS 205) are compared based on their security assumptions, performance, and readiness for deployment. The practical limitations and the use of Quantum Key Distribution, (QKD), as a physics based alternative to the computational security assumptions are discussed. Results show that although mature PQ solutions are now available for most cryptographic applications, the migration challenge, including legacy system transitions, migration architecture, and governance, is significant and pressing as the ‘harvest now, decrypt later’ threat model is relevant and adversaries might be collecting encrypted data for quantum decryption. The impact for financial services, health care, government, cloud infrastructure and critical national infrastructure is discussed. Lastly, the researchers list key research areas: standardisation of quantum-safe protocols, hybrid PQC-QKD designs, light-weight PQC for constrained devices, and quantum-safe blockchain.
The maturation of quantum computing hardware and algorithms has transformed what was once a theoretical concern into an active planning priority for governments, enterprises, and standards bodies. This paper assesses the current and projected threat that quantum computation poses to classical public-key cryptographic standards, namely RSA, elliptic curve cryptography (ECC), and Diffie-Hellman key exchange, all of which derive their security from mathematical problems that Shor's algorithm renders tractable on a sufficiently large fault-tolerant quantum computer. We synthesize recent hardware progress, algorithmic refinements that have substantially reduced estimated qubit requirements, and the finalization of NIST's post-quantum cryptography (PQC) standards (FIPS 203, 204, and 205) to provide an evidence-based assessment of where the field stands as of mid-2026. Particular attention is given to the widening gap between optimistic resource estimates, including a contested March 2026 claim of a thousand-fold reduction in factoring resources, and the practical reality that no existing quantum computer approaches the logical qubit counts required to threaten deployed encryption. We further examine migration challenges, including performance overhead, cryptographic agility, constraints on embedded and IoT systems, and the harvest-now-decrypt-later threat model that makes migration urgency independent of exact timeline predictions. Drawing on NIST transition guidance and recent G7 coordination targets, we argue that organizations should treat cryptographic migration as a present-tense operational requirement rather than a future contingency, regardless of unresolved disagreement among experts about when a cryptographically relevant quantum computer will exist. The paper concludes with practical recommendations for risk-based migration prioritization and identifies open research questions in cryptographic agility and quantum-resistant system design.
Quantum computing represents a significant threat to the asymmetric cryptographic algorithms currently used to protect the traditional data security infrastructure today’s enterprises depend upon. With Gartner predicting that by 2029 advances in quantum computing will render applications, data and networks protected by asymmetric cryptography unsafe, organisations must begin preparations to transition to post-quantum cryptography (PQC). Organisations that fail to prepare for quantum today risk potentially exposing their sensitive data on a massive scale, as threat actors are already collecting encrypted enterprise data in anticipation of future quantum decryption capabilities. The migration to PQC involves updating risk registers and enabling the crypto agility that supports the rapid implementation of new algorithms and ensures organisations can adapt fast to new regulatory standards.
A new era of digital security may be on the horizon as well as the disruption of current cryptographic methods brought about by the arrival of quantum computing, which represents a dramatic change in the cybersecurity landscape. Many existing cryptographic systems, like RSA and ECC, rely on solving complicated mathematical problems; quantum computers, with their unparalleled processing capability, are capable of doing just that (Elliptic Curve Cryptography). Concerns over the security of sensitive information, online identities, and communications in the post-quantum era are heightened by these vulnerabilities. In order to protect digital infrastructures, this study investigates the potential effects of quantum computing on cybersecurity and the critical need for encryption that is immune to quantum attacks. The creation of new cryptographic algorithms that are resistant to quantum assaults is becoming increasingly urgent as the field of quantum computing advances, posing an existential danger to traditional encryption systems. A number of possible methods for protecting data against quantum computers are discussed in the study. These methods include code-based cryptmography, lattice-based cryptography, hash-based cryptography, and multivariate polynomial cryptography. Scalability, computing efficiency, and compatibility with existing systems are some of the possible obstacles to moving to quantum-resistant systems that are covered in the article. By delving deeply into the effects of quantum computing on cybersecurity, this study highlights the significance of getting ready for a quantum future and the function of quantum-safe encryption in making sure that digital security solutions can withstand the rise of quantum technology.