The Need for Quantitative Resilience Models and Metrics in Classical-Quantum Computing Systems

TL;DR

It is stated here that resilience must become an a priori design constraint rather than an afterthought of HPC-QPU integration, and how resilience methods in civil engineering can apply at various levels of the classical-quantum computing stack is suggested.

Abstract

Increasingly deeper integration of HPC resources and QPUs unveils new challenges in computer architecture and engineering. As a consequence, dependability arises again as a concern encompassing resilience, reproducibility and security. The properties of quantum computing systems involve a reinterpretation of these factors in retrodictive, predictive, and prescriptive ways. We state here that resilience must become an \emph{a priori} design constraint rather than an afterthought of HPC-QPU integration. This article describes the need for conceptual and quantitative models to estimate and assess the resilience hybrid classical-quantum computing infrastructure. We suggest how resilience methods in civil engineering can apply at various levels of the classical-quantum computing stack. We also discuss implications of a model of end-user value for the estimation of consequences resulting from the propagation of vulnerabilities from a given level of the stack upwards. Finally, we argue in favor of new resilience models can help the impact of improving specific components in quantum technology stacks to provide a clearer picture about the value of separation of concerns across different layers. Ultimately, HPC-QPU integration will increasingly demand more precise statements about the cost-benefit ratio of specific system improvements and their cascading consequences against estimates of delivered value to users.

Figures (9)

• Figure 1: Intersecting aspects of dependability in Classical-Quantum Computer Systems. Reproduced from giusto2024dependable.
• Figure 2: Combined fault class diagram used in classical dependability and resilience analysis. Reproduced from avizienis2001fundamental.
• Figure 3: Combined fault class diagram for stimuli challenging DCQCS resilience. Blue, dashed line: quantum testbed, miscalibrated qubits. Blue, solid line: quantum control ASIC microfabrication error. Orange, dashed line: malicious data snooping software embedded in an open source quantum compilation toolchain used by experimentalists. Orange, solid line: malicious noise injection in VQE execution using magnetic interference equipment. Adapted from giusto2025typology.
• Figure 4: Dependable Classical-Quantum Computer Systems Engineering as a negative material design problem. The difficulty of obtaining a DCQCS can be explained at large by the need to traverse the space of governing laws of coupled classical-quantum systems with limited orienting features and a starting non-solution. Adapted from nunez2020toward.
• Figure 5: Classes of systems from the perspective of the time-dependent response of dynamical systems to various kinds of perturbations. Reproduced from axenie2023antifragility.