The emergence of large-scale quantum computing presents a fundamental challenge to widely deployed classical cryptographic systems.Public-key algorithms such as RSA and Elliptic Curve Cryptography (ECC) rely on mathematical problems that are considered computationally infeasible for classical computers but can potentially be solved efficiently by sufficiently capable quantum computers using Shor's algorithm.Symmetric cryptography is less severely affected, although Grover's algorithm reduces the effective security provided by a fixed key length.Replacing every existing cryptographic system immediately with post-quantum cryptography is neither technically nor operationally straightforward.Financial institutions, government organisations and large enterprises operate extensive cryptographic infrastructures involving legacy applications, APIs, certificates, hardware security modules, databases, digital signatures, mobile applications and third-party systems.This paper proposes a Classical Cryptography Quantum Hardening Framework (CCQHF) that combines cryptographic inventory, risk classification, hybrid cryptographic mechanisms, increased symmetric-key strength, cryptographic agility, key-management improvements and staged adoption of post-quantum cryptography.The framework does not claim to make RSA or ECC resistant to Shor's algorithm.Instead, it proposes a controlled architecture in which classical cryptography is retained where appropriate while quantum-vulnerable components are protected through hybrid mechanisms and ultimately replaced by standardised post-quantum algorithms.
The emergence of large-scale quantum computing presents a fundamental challenge to widely deployed classical cryptographic systems.Public-key algorithms such as RSA and Elliptic Curve Cryptography (ECC) rely on mathematical problems that are considered computationally infeasible for classical computers but can potentially be solved efficiently by sufficiently capable quantum computers using Shor's algorithm.Symmetric cryptography is less severely affected, although Grover's algorithm reduces the effective security provided by a fixed key length.Replacing every existing cryptographic system immediately with post-quantum cryptography is neither technically nor operationally straightforward.Financial institutions, government organisations and large enterprises operate extensive cryptographic infrastructures involving legacy applications, APIs, certificates, hardware security modules, databases, digital signatures, mobile applications and third-party systems.This paper proposes a Classical Cryptography Quantum Hardening Framework (CCQHF) that combines cryptographic inventory, risk classification, hybrid cryptographic mechanisms, increased symmetric-key strength, cryptographic agility, key-management improvements and staged adoption of post-quantum cryptography.The framework does not claim to make RSA or ECC resistant to Shor's algorithm.Instead, it proposes a controlled architecture in which classical cryptography is retained where appropriate while quantum-vulnerable components are protected through hybrid mechanisms and ultimately replaced by standardised post-quantum algorithms.
The rapid advancement of quantum computing introduces unprecedented security threats to modern cloud and edge computing infrastructures. Classical public-key cryptographic algorithms such as RSA, Diffie–Hellman, and Elliptic Curve Cryptography (ECC) are fundamentally vulnerable to quantum attacks enabled by Shor’s algorithm. As a result, the confidentiality, integrity, and authenticity of data stored and processed in distributed systems are at serious risk.Post-quantum cryptography (PQC) aims to develop cryptographic algorithms that are resistant to both classical and quantum adversaries. This paper presents a comprehensive quantum-resilient cryptographic framework designed specifically for post-quantum cloud and edge computing environments. The framework integrates post-quantum cryptographic primitives, hybrid cryptographic approaches, crypto-agile architectures, and secure key management mechanisms. The proposed framework addresses performance constraints, scalability requirements, and deployment challenges in heterogeneous environments. A detailed discussion of security threats, architectural components, performance considerations, and future research directions is provided. The proposed approach enables longterm security and supports a smooth transition toward quantum-safe distributed computing systems.
Abstract—The emergence of quantum computing represents a fundamental challenge to contemporary cryptographic infras- tructures, mandating immediate adoption of quantum-resistant cryptographic standards to ensure long-term security. This paper analyzes how Shor’s algorithm renders RSA , ECC vulnerable by solving integer factorization and discrete alogarithm problems in polynomial time, while Grover’s algorithm weakens symmetric encryption through quadratic speedup attacks. Through compre- hensive cryptanalysis, we evaluate the vulnerabilities of current public-key infrastructures, symmetric ciphers, and hash functions against quantum threats. Our research systematically examines post-quantum cryptographic candidates, including lattice-based, hash-based, and multivariate polynomial schemes under NIST standardization, assessing their security guarantees and imple- mentation challenges. Furthermore, we investigate the broader implications for secure communications, blockchain networks, and authentication protocols in a post-quantum world. Based on our findings, we propose a practical transition framework featuring hybrid cryptographic systems, protocol enhancements, and policy updates to facilitate seamless migration. This work provides critical insights and actionable strategies for securing digital infrastructure against quantum threats while maintaining operational efficiency during the transition period. Index Terms—Cryptographic vulnerability, Grover’s algo- rithm, Post-quantum cryptography, Quantum computing, Quan- tum key distribution, Shor’s algorithm, Cybersecurity
The rapid advancement of quantum computing presents a significant challenge to classical cryptographic systems that underpin modern digital security infrastructures. In particular, RSA-2048 encryption, widely deployed in banking and financial institutions for secure transactions, relies on the computational hardness of integer factorization. However, the emergence of quantum algorithms—especially Shor’s algorithm—poses a fundamental threat to RSA security by enabling polynomial-time factorization of large integers on sufficiently powerful quantum computers. This case study investigates the vulnerability of RSA-2048 within a banking environment, analyzing the mathematical foundations of the threat, potential timelines for quantum feasibility, and associated cybersecurity risks. The study further examines the implications for financial data protection, digital signatures, and secure communication channels. In response to these emerging risks, the paper explores post-quantum cryptographic alternatives, including lattice-based, hash-based, and code-based schemes, and evaluates their suitability for banking applications. The findings emphasize the urgency of transitioning toward quantum-resistant cryptographic frameworks and propose strategic recommendations for proactive cryptographic migration to ensure long-term data confidentiality and system resilience.
The emergence of quantum computing presents both significant opportunities and critical challenges for modern cybersecurity. While quantum systems promise advances in science, engineering, and artificial intelligence, they also pose a substantial threat to classical cryptographic techniques such as RSA, ECC, and other widely deployed public-key mechanisms. Quantum algorithms including Shor’s and Grover’s are expected to compromise these systems, placing sensitive data, financial infrastructures, and national security at risk. This paper examines the growing field of quantum-resistant, or post-quantum, cryptography with a focus on identifying constructions capable of withstanding quantum attacks. It provides a systematic overview of major post-quantum cryptographic families, including lattice-based, hash-based, code-based, multivariate, and isogeny-related schemes, and evaluates their current security assumptions, practical efficiency, and readiness for real-world deployment. Beyond technical considerations, the paper highlights the organizational and workforce implications of transitioning to quantum-safe systems, emphasizing the need for coordinated global standards and sustained cybersecurity training. This study underscores that building a quantum-secure digital future requires not only adopting resilient algorithms but also strengthening collaborative, adaptive, and proactive security practices.
“Cryptographic Implications of Quantum Computing” explores the significant impact quantum computing will have on modern cryptographic systems. Cryptography is essential for maintaining confidentiality, integrity, and authenticity in digital communications, safeguarding critical infrastructure, and building trust in the digital economy. As quantum computing advances, traditional cryptographic systems will face new challenges. Also this chapter examines Shor's Algorithm, which poses a major threat to RSA and Elliptic Curve Cryptography (ECC) by enabling quantum computers to efficiently solve the prime factorization and discrete logarithm problems, breaking these widely used public key cryptosystems. The potential of Grover's Algorithm is also discussed, highlighting its ability to speed up brute-force attacks on symmetric encryption systems like AES, halving the security of traditional symmetric-key algorithms. To mitigate these threats, the chapter suggests adopting AES-256 or longer key lengths, which are more resistant to quantum attacks, and recommends shifting to quantum-resistant algorithms for both symmetric and asymmetric encryptions. However, practical considerations, such as increased computational overhead and the challenges of transitioning to new systems, are also explored. The vulnerabilities of classical cryptographic systems particularly public-key methods like RSA and ECC, and symmetric key algorithms like AES and DES are examined in light of the capabilities of quantum computers. As quantum computing progresses, it is crucial for organizations and governments to adapt and adopt post-quantum cryptography to ensure data security in the quantum era. The chapter emphasizes the need for a proactive approach to protect sensitive information against the emerging quantum threats.
The rapid progress of quantum computing is changing the assumptions on which many modern security systems are built. Public-key methods such as RSA and Elliptic Curve Cryptography (ECC) remain dependable against conventional computers, yet their underlying mathematical problems can be solved efficiently by a sufficiently capable quantum computer using algorithms such as Shor's algorithm. This creates a practical need to evaluate cryptographic techniques that can continue to protect information in a post-quantum environment. This study compares representative classical algorithms - RSA, ECC, and the Advanced Encryption Standard (AES) - with post-quantum approaches, with particular attention to CRYSTALS-Kyber and CRYSTALS-Dilithium. The comparison considers security assumptions, key-generation cost, encryption and decryption time, key size, memory demand, and resistance to quantum attacks. The reported benchmark values indicate that RSA has the highest processing cost among the evaluated schemes, whereas CRYSTALS-Kyber provides comparatively fast key generation, encryption, and decryption while maintaining resistance to known quantum attacks. The study also discusses a hybrid migration model in which established classical mechanisms and post-quantum algorithms operate together during the transition period. Overall, the findings support a gradual move toward quantum-resistant communication systems while recognising the deployment and storage overhead introduced by larger post-quantum keys.