相干性而非错误率主导多租户量子计算中的隐私
Coherence Rather Than Error Rate Governs Privacy in Multi-Tenant Quantum Computing
- The University of Melbourne（墨尔本大学）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本文提出基于量子态可区分性的信息泄漏度量，实验表明相干错误主导跨租户信息泄漏，均匀泡利随机化可将其降至零，并呼吁云量子提供商报告泄漏指标。
中文摘要 AI 辅助
多租户计算使商业云量子处理器的提供商能够将设备的互不相交扇区租给独立用户。云量子计算提供商报告的平均门错误率并不能决定一个租户能了解到另一个租户的多少信息。我们提出了一种基于量子态可区分性的信息论概念，用于衡量跨共租边界的信息泄漏。我们在商用156量子比特（IBM Kingston）和20量子比特（IQM Garnet）设备上测量了这种泄漏。具有相同基准错误率的边界可能提供显著不同的信息泄漏量，因为标准报告的错误度量对错误的相干性与随机性本质不敏感，而我们提出的信息泄漏概念则对此敏感。在受害者的整个寄存器上实施均匀泡利随机化作为防御机制，可将信息泄漏降至零。该防御在理论上不产生保真度代价，但实验显示由错误累积引起的非平凡退化。我们向量子云计算提供商提出具体行动呼吁，要求在其设备数据表中除标准错误率外还报告信息泄漏，以便用户在使用设备前计算隐私和安全风险。
英文摘要
Multi-tenant computing enables providers of commercial cloud quantum processors to rent disjoint sectors of a device to independent users. Average gate error, which cloud quantum computing providers report, does not determine how much one tenant learns about another. We propose an information-theoretic notion of information leakage across co-tenancy boundaries stemming from quantum state distinguishability. We measure this leakage on commercially-available 156-qubit (IBM Kingston) and 20-qubit (IQM Garnet) devices. Boundaries with identical benchmarked error can offer significantly different amount of information leakage because standard reported measures of error are blind to coherent-versus-stochastic nature of the error while the proposed notion of information leakage is not. A uniform Pauli randomisation implemented over the victim's whole register is used as a defence mechanism to reduce the information leakage to zero. The defence theoretically does not incur a fidelity cost, but the experiments show a non-trivial degradation caused by accumulation of errors. We provide a specific call-for-action to the providers of quantum cloud computing to report information leakage in addition to standard error rates in their device datasheet to enable users to compute privacy and security risks prior to engagement with the device.
