Abstract Quantum computing represents a fundamentally new computational paradigm based on quantum-mechanical phenomena such as superposition, entanglement, and quantum tunneling. These effects enable certain computational tasks to be performed more efficiently than on classical digital computers. In theory, quantum computing promises significant reductions in execution time and potentially improved energy efficiency for specific classes of problems. The slowing of traditional hardware scaling trends — often associated with Moore’s Law — combined with advances in nanoscale control technologies, has led to substantial commercial and national-security investments in quantum technologies throughout the 2010s. A landmark moment occurred when Google announced the demonstration of so-called quantum supremacy using its superconducting quantum processor Sycamore. The experiment showed that a quantum device could perform a specific computational task beyond the practical reach of classical supercomputers. While the task itself had no immediate practical application, the demonstration marked a critical milestone in the evolution of quantum computing and provided a concrete benchmark for future developments. Quantum Computing and Information Security The rapid progress of quantum technologies introduces significant implications for information security. Many modern cryptographic systems rely on the computational difficulty of mathematical problems such as: Integer factorization Discrete logarithms Elliptic curve problems Quantum algorithms — most notably Shor’s algorithm — threaten to efficiently solve these problems once sufficiently large, fault-tolerant quantum computers become available. This creates a long-term risk to widely deployed public-key cryptosystems, including RSA and elliptic curve cryptography. Through practical experimentation on the IBM Q platform, it becomes possible to: Implement and test fundamental quantum algorithms. Simulate cryptographic primitives under quantum attack models. Evaluate the scalability and limitations of current hardware. Explore post-quantum mitigation strategies. Although current quantum devices remain in the NISQ (Noisy Intermediate-Scale Quantum) era and are not yet capable of breaking real-world cryptographic systems, the trajectory of development suggests that cryptographic transition planning must begin well before large-scale quantum computers emerge. Strategic Implications The quantum threat to information security is not immediate but is strategically significant: Encrypted data intercepted today may be decrypted in the future ("harvest now, decrypt later"). Critical infrastructure and national security systems require long-term protection horizons. Migration to quantum-safe cryptographic standards must occur proactively. Practical experience using IBM Q demonstrates both the power and current limitations of quantum systems, providing valuable insight into how theoretical quantum threats translate into real-world technological development.
Abstract Quantum computing represents a fundamentally new computational paradigm based on quantum-mechanical phenomena such as superposition, entanglement, and quantum tunneling. These effects enable certain computational tasks to be performed more efficiently than on classical digital computers. In theory, quantum computing promises significant reductions in execution time and potentially improved energy efficiency for specific classes of problems. The slowing of traditional hardware scaling trends — often associated with Moore’s Law — combined with advances in nanoscale control technologies, has led to substantial commercial and national-security investments in quantum technologies throughout the 2010s. A landmark moment occurred when Google announced the demonstration of so-called quantum supremacy using its superconducting quantum processor Sycamore. The experiment showed that a quantum device could perform a specific computational task beyond the practical reach of classical supercomputers. While the task itself had no immediate practical application, the demonstration marked a critical milestone in the evolution of quantum computing and provided a concrete benchmark for future developments. Quantum Computing and Information Security The rapid progress of quantum technologies introduces significant implications for information security. Many modern cryptographic systems rely on the computational difficulty of mathematical problems such as: Integer factorization Discrete logarithms Elliptic curve problems Quantum algorithms — most notably Shor’s algorithm — threaten to efficiently solve these problems once sufficiently large, fault-tolerant quantum computers become available. This creates a long-term risk to widely deployed public-key cryptosystems, including RSA and elliptic curve cryptography. Through practical experimentation on the IBM Q platform, it becomes possible to: Implement and test fundamental quantum algorithms. Simulate cryptographic primitives under quantum attack models. Evaluate the scalability and limitations of current hardware. Explore post-quantum mitigation strategies. Although current quantum devices remain in the NISQ (Noisy Intermediate-Scale Quantum) era and are not yet capable of breaking real-world cryptographic systems, the trajectory of development suggests that cryptographic transition planning must begin well before large-scale quantum computers emerge. Strategic Implications The quantum threat to information security is not immediate but is strategically significant: Encrypted data intercepted today may be decrypted in the future ("harvest now, decrypt later"). Critical infrastructure and national security systems require long-term protection horizons. Migration to quantum-safe cryptographic standards must occur proactively. Practical experience using IBM Q demonstrates both the power and current limitations of quantum systems, providing valuable insight into how theoretical quantum threats translate into real-world technological development.
Abstract Quantum computing leverages fundamental quantum-mechanical phenomena—most notably superposition, entanglement, and quantum tunneling—to perform computations in ways that differ fundamentally from classical digital processing. Compared to conventional computing architectures, quantum systems promise significant reductions in computational time and potentially lower energy consumption for specific classes of problems. These advantages, combined with advances in nanoscale engineering and the slowing of traditional hardware scaling trends such as Moore’s Law, have led to substantial commercial and national-security-driven investments in quantum technologies over the past decade. A major milestone was reached when Google announced the experimental demonstration of “quantum supremacy,” showing that a quantum processor could execute a specific computational task infeasible for a classical supercomputer within practical time constraints. Although the demonstrated problem had no immediate practical application, this achievement marked a crucial step toward the development of quantum systems capable of delivering real-world computational advantages and provided a more precise technical framing of the concept of quantum advantage. Despite the fact that the mathematical foundations, programming models, and principal quantum algorithms were established in the 1990s, quantum computing remained largely confined to a specialized research community for decades. Today, the increasing accessibility of cloud-based quantum hardware calls for a broader dissemination of implementation-oriented knowledge among researchers and practitioners in computer science, software engineering, and related fields. The quantum programming paradigm differs fundamentally from classical programming models and often relies on physical and algebraic notations that may pose barriers to traditionally trained computer scientists. This series of articles provides a self-contained and concise introduction to quantum computing and its core algorithms, with a strong emphasis on practical implementation. Given that real quantum processors—such as those accessible via the IBM quantum ecosystem—are now available as cloud services, experimental validation can be conducted both on simulators and on actual hardware for small-scale inputs. While other platforms such as Rigetti and IonQ also offer cloud-based quantum computing services, this review focuses exclusively on the IBM quantum computing ecosystem.
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.
Abstract Classical computing architectures cannot reasonably solve computationally challenging problems, such as those of RSA public-key encryption, Diffie-Hellman key exchange, and elliptic curve cryptography, which form the cryptographic foundations of modern enterprise information security. Superposition and entanglement phenomena can be used to make quantum computers efficient in solving these problems, which are efficiently solved by Shor's algorithm and Grover's algorithm, and make existing cryptographic infrastructure entirely insecure. While quantum computing is fault-tolerant and still under development, the 'harvest now, decrypt later' threat model by which adversaries can harvest encrypted data now to be decrypted later when they can operate quantum systems signals that the cryptographic threat is present, not future. The objective of this study is to examine the current state of enterprise cryptographic readiness against threats in the quantum era and to create a model for organizational transition to the new cryptographic standards in the quantum era, which is called the Quantum-Resilient Security Architecture (QRSA) Framework. It uses a mixed-methods research methodology, consisting of a systematic literature review, an expert Delphi survey of 38 cybersecurity practitioners from 16 countries, and a qualitative analysis of five enterprise organizations, to examine the state of quantum-capable cryptographic protocols, the readiness of organizations in the technical, governance and capability aspects, and the most important enablers and blockers for the post-quantum migration. The key findings include that: 94 percent of enterprise systems assessed are today still using quantum-vulnerable cryptographic primitives; less than 12 percent of organizations surveyed have started formal planning efforts for quantum migration; and, in most of the cases analyzed, the National Institute of Standards and Technology (NIST) post-quantum cryptography standardization process has not made significant impacts on enterprise security roadmaps. The QRSA Framework offers a staged migration architecture based on the NIST standardized algorithms such as CRYSTALS-Kyber, CRYSTALS-Dilithium and SPHINCS+ that integrates with the enterprise security infrastructure. Contributions include cybersecurity governance scholarship, enterprise risk management theory, and information security policy.
Quantum computing is a transformational technology once implemented, capable of addressing problems far beyond the capacity of classical computers. But this progress is also a real challenge to the core of today's modern security. Traditional cryptographic algorithms, such as those based on RSA, ECC, and Diffie-Hellman key exchange, are based on the computational hardness of problems such as prime factorization and discrete logarithms that quantum algorithms solve in polynomial time. As a particular research interesting example, with Shor's Algorithm one can factorize large numbers efficiently, rendering insecure the majority of public key cryptosystems used nowadays. This urgently demands a reevaluation of existing encryption schemes in the context of a post-quantum world. In this paper, we take a closer look at the threats that quantum computers pose to classical security infrastructure including encryption scheme and explore the impact that quantum computation can have on current cryptographic schemes. It calculates the cost in terms of symmetric and asymmetric security, accounting for effects of both Shor's and Grover's algorithms. Symmetric key systems such as AES are also harder hit—Grover's algorithm can give only a quadratic speedup here—but they do need to double key sizes for a sufficient level of post-quantum security. In reaction to those threats, the paper investigates nextgeneration post-quantum cryptographic (PQC) solutions resistant to quantum cryptanalysis. Lattice-based cryptosystems, hash-based signature schemes, multivariate polynomial systems, and code-based cryptosystems are some of the candidates that are being considered in international standardization work, including especially at NIST. In this paper, we compare those alternatives for security, performance, scalability, and feasibility of implementation in real system. An important aspect of this contribution is a comparative study of traditional and post-quantum cryptographic protocols in the context of a number of cybersecurity applications, including secure communications, blockchain networks and IoT contexts. It also covers the quantum readiness timeline and transitional issues, such as backward compatibility, standardization lag and the associated increased computational overhead. Through a mitigated risk evaluation and cryptanalytic attack simulation based on quantum-inspired algorithms, this analysis emphasizes the need to prepare ourselves against quantum-induced security issues. It provides strategic guidance to organizations as they plan for the post-quantum future, stressing cryptographic agility, hybrid encryption models and real-time threat monitoring. Ultimately, the results of this work add to the worldwide conversation on establishing secure systems within the digital age of quantum computing and recommend proactive migration plans for the integrity, confidentiality, and trust one should have in the future cyber world.
The rapid advancement of quantum computing poses both transformative opportunities and profound challenges for modern cybersecurity and cryptography. Unlike classical computers, quantum systems leverage the principles of quantum mechanics-superposition, entanglement, and quantum tunneling-to process information in fundamentally new ways, enabling exponentially faster computation for certain problems. This paradigm shift threatens to render many of today's widely adopted cryptographic algorithms obsolete, particularly those relying on the hardness of integer factorization (e.g., RSA) and discrete logarithms (e.g., ECC and DSA). Quantum algorithms, such as Shor's algorithm, have the potential to break these cryptosystems in polynomial time, exposing sensitive data to unprecedented levels of vulnerability. Additionally, Grover's algorithm accelerates brute-force attacks on symmetric encryption schemes, reducing their effective security strength by half. This paper explores the implications of quantum computing on current cryptographic infrastructures, highlighting the urgency for transitioning to quantum-resistant or postquantum cryptographic algorithms. It examines emerging standards from bodies such as NIST, which are fostering the development and evaluation of lattice-based, codebased, multivariate polynomial, and hash-based cryptographic solutions. Furthermore, the study delves into the dual-edged nature of quantum computing in cybersecuritydiscussing its potential not only as a threat but also as a powerful tool for enhancing security through quantum key distribution (QKD), quantum random number generation, and other quantum-enhanced protocols. The work concludes by evaluating the readiness of current systems for the "quantum threat," identifying gaps in awareness, infrastructure, and policy, and proposing a strategic roadmap for a secure transition into the post-quantum era. As the quantum revolution accelerates, understanding and preparing for its cybersecurity ramifications is not merely a technical necessity but a cornerstone of global digital resilience.
Quantum computing’s arrival signals a paradigm shift in computational power that may transform several sectors, including drug discovery, artificial intelligence, materials research, and optimization [2]. However, this transformative potential also presents a significant and imminent threat to cybersecurity. At the heart of this technological shift is the ability of quantum computers to tackle the complex mathematical challenges on which modern public-key cryptography relies. Quantum algorithms, most notably Shor’s algorithm, can break problems such as integer factorization and discrete logarithms far more efficiently than classical approaches. As a result, cryptographic methods that are widely trusted today—including RSA and Elliptic Curve Cryptography (ECC)—could become insecure once large-scale quantum computing becomes a reality[1], [8].This poses a profound challenge to the confidentiality, integrity, and authenticity of digital communications, financial networks, essential infrastructure, and national defense systems [9]. To counter this emerging risk, Post-Quantum Cryptography (PQC) has become an important area of active research. The goal of PQC is to design cryptographic techniques that can withstand attacks from both conventional computers and future quantum systems, thereby preserving long-term data security in the face of advancing quantum technologies [3].A number of promising Post-Quantum Cryptography (PQC) approaches are currently being explored in depth. Among them, lattice-based cryptography has attracted significant interest, as it relies on the computational difficulty of problems like Learning With Errors (LWE) and the Shortest Vector Problem (SVP), offering both robust security assurances and practical efficiency [4], [5]. Hash-based signature schemes, such as XMSS and SPHINCS+, offer security rooted in well-established hashing techniques and stateless signature construction [7]. Additionally, code-based cryptography, including systems inspired by the McEliece cryptosystem, remains attractive for its long-standing resistance to cryptanalytic attacks [6]. Other avenues include multivariate quadratic systems and isogeny-based cryptography, each presenting unique benefits and trade-offs in terms of key size, performance, and security robustness [8].A central force driving global standardization is the NIST Post-Quantum Cryptography Standardization Project, initiated in 2016 to evaluate and establish new quantum-resilient cryptographic standards [3]. Several algorithms have already advanced to the final standardization phase, while others remain candidates for further evaluation.Despite this progress, transitioning to PQC introduces practical challenges. Integrating new cryptographic algorithms into current digital ecosystems demands considerable computational and infrastructural updates, often involving larger key sizes and increased processing overhead [10]. Organizations must also ensure crypto-agility, the capability to rapidly adapt cryptographic systems as new standards evolve or vulnerabilities are identified [11].One strategic transition approach involves hybrid cryptographic architectures, which combine conventional and quantum-safe algorithms to provide layered security during this migration period [9]. Moreover, organizations should inventory existing cryptographic assets, conduct quantum risk assessments, pilot PQC deployments, and cultivate a quantum-aware cybersecurity workforce.The threat is amplified by “harvest now, decrypt later” strategies, in which adversaries intercept encrypted data today with the intention of decrypting it once quantum capabilities mature [9]. Particularly sensitive categories — including military communications, governmental archives, personal healthcare records, and intellectual property — require immediate PQC-oriented protection.As the quantum era approaches, coordinated global action is essential to harness quantum innovation while safeguarding digital trust. Through proactive investment in research, standardization efforts, and phased post-quantum deployment, societies can preserve digital sovereignty and security resilience in the face of this technological shift [11].