Title Towards a unified quantum risk assessment
Authors Grigaliūnas, Šarūnas ; Brūzgienė, Rasa
DOI 10.3390/electronics14173338
Full Text Download
Is Part of Electronics.. Basel : MDPI. 2025, vol. 14, iss. 17, art. no. 3338, p. 1-18.. ISSN 2079-9292
Keywords [eng] quantum risk assessment ; post-quantum cryptography ; Mosca’s inequality ; quantum-adjusted risk score (QARS) ; crypto-agility ; PAREK framework ; timeline risk ; exposure risk ; data sensitivity ; EU’s coordinated PQC roadmap
Abstract [eng] 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.
Published Basel : MDPI
Type Journal article
Language English
Publication date 2025
CC license CC license description