Machine-learning (ML) classifiers are increasingly used in quantum computing systems to improve multi-qubit readout discrimination and to mitigate correlated readout errors. These ML classifiers are an integral component of today's quantum computer's control and readout stacks. This paper is the first to analyze the susceptibility of such ML classifiers to physical fault-injection which can result in generation of incorrect readout results from quantum computers. The study targets 5-qubit (thus 32-class) readout error-correction model. Using the ChipWhisperer Husky for physical voltage glitching, this work leverages an automated algorithm for scanning the fault injection parameter search space to find various successful faults in all the layers of the target ML model. Across repeated trials, this work finds that fault susceptibility is strongly layer-dependent: early-layers demonstrate higher rates of misprediction when faults are triggered in them, whereas later layers have smaller misprediction rates. This work further characterizes the resulting readout failures at the bitstring level using Hamming-distance and per-bit flip statistics, showing that single-shot glitches can induce structured readout corruption rather than purely random noise. These results motivate treating ML-based quantum computer readout and readout correction as a security-critical component of quantum systems and highlight the need for lightweight, deployment-friendly fault detection and redundancy mechanisms in the quantum computer readout pipelines.
翻译:机器学习分类器在量子计算系统中日益广泛地应用于改进多量子比特读出判别与缓解相关读出误差。这些ML分类器已成为当代量子计算机控制与读出堆栈的核心组成部分。本文首次分析了此类ML分类器对物理故障注入的脆弱性,此类攻击可导致量子计算机产生错误的读出结果。本研究针对5量子比特(即32类别)的读出误差校正模型展开。通过使用ChipWhisperer Husky进行物理电压毛刺注入,本工作采用自动化算法扫描故障注入参数搜索空间,在目标ML模型的所有层级中成功诱发多种故障。在重复试验中,本研究发现故障脆弱性具有显著的层级依赖性:当故障在前端层级触发时,其误判率更高;而后端层级的误判率相对较低。本研究进一步通过汉明距离和逐比特翻转统计,在比特串层面对引发的读出故障进行表征,结果表明单次毛刺注入可诱发结构化读出损坏,而非纯粹的随机噪声。这些研究结果促使我们将基于机器学习的量子计算机读出及读出校正视为量子系统的安全关键组件,并凸显了在量子计算机读出流水线中部署轻量级、易于集成的故障检测与冗余机制的必要性。