Quantum Cryptography Analysis For Threat Assessment

Šarūnas Grigaliūnas, Rasa Brūzgienė

Quantum computing poses an unprecedented threat to classical cryptography, requiring new risk assessment paradigms. This paper proposes a Quantum-Adjusted Risk Score (QARS) model, a theoretical and methodological innovation within the EU’s PAREK framework (Post-quantum asset and algorithm inventory, risk assessment, road mapping, execution, key governance). QARS extends Mosca’s inequality—which defines a quantum threat timeline threshold—into a multi-factor risk scoring formula. We formalise QARS with mathematical expressions incorporating timeline, sensitivity, and exposure dimensions, each calibrated by factor weights and scaling functions. The design motivations for including these dimensions are discussed in depth. We present method for model calibration (including sector-specific weight adjustments) and outline validation strategies combining quantitative analysis and expert judgement. The proposed QARS model is situated in the context of the EU’s coordinated roadmap for post-quantum cryptography and cybersecurity regulations, illustrating how QARS supports compliance and strategic migration prioritisation. A prototype tool implementing QARS model is also provided to demonstrate practical applicability. Our contributions provide a unified approach to quantum risk assessment, marrying theoretical rigour with policy-relevant risk management needs to help organizations proactively address the quantum threat.

Neha Diwaker, Babita Gupta, Nibh Kumari +1 more

nbspVenkatesh Prasad. G, nbspRohit A S Nair, S nbspNagamani +1 more

Md. Mehedi Hasan, Mohammad Kamrul Hasan, Nazatul Hafizah +2 more

The recent advancement of smart grid systems, integrating cyber-physical systems with information and communication technologies enables real-time monitoring, control, and data transmission. However, these operations often inherently insecure communication infrastructures increasing exposure to cyber threats and data breaches. Consequently, cryptographic authenticated and key agreement protocols address cyber-attacks, threats, and vulnerabilities to protect data privacy and security in smart grid. Meanwhile, quantum computing progression is rapidly footprinted in real-world application thus quantum computing-based Grover's and Shor’s algorithm is capable for breaking classical cryptographic algorithms mathematical advances. Therefore, this review explores the adaptability of quantum computing, examines its impact on classical cryptography vulnerabilities, and highlights the role of quantum cryptography in enhancing security and scalability of smart grid cyber-physical systems. Accordingly, a comparative analysis was conducted to assess the security and performance of Rivest-Shamir Adleman, elliptic curve cryptography and digital signature algorithms against quantum cryptography for highlighting their respective strengths and limitations in quantum era context. This review provides a foundation of future researchers for integrate quantum technology and develop quantum-resilient solutions that overcome the constraints of classical cryptography.

Manik Rakhra, Rajeev Kanday, Gaurav Aggarwal +3 more

The current research focuses on quantum cryptography as a suitable solution of communication security given the growing quantum computing threat. Since RSA and ECC algorithms are becoming more and more susceptible to quantum algorithms, new quantum-resistant algorithms are required. In present work, an empirical and theoretical analysis is applied to assess the efficiency of QKD protocols – BB84 and Continuous Variable QKD – compared to the established CSPs. Some of the key findings include demonstrating provable security of information via QKD, defending against eavesdropping compared to failing classical systems. The future applications of quantum cryptography are described in organizations and areas of concern like health and finance, to secure and improve security and regulatory procedures. Also, the work seeks to look at the parity between classical and quantum computing structures with blended approaches as a more viable approach to scaling up. Solving integration and scalability issues, this research lays a foundation for implementing quantum cryptography around the world during the digital era.

Dr.Geetha V Dr. Sharadadevi Kaganurmath