In the main text published at USENIX Security 2025, we presented a systematic analysis of the role of cache occupancy in the design considerations for randomized caches (from the perspectives of performance and security). On the performance front, we presented a uniform benchmarking strategy that allows for a fair comparison among different randomized cache designs. Likewise, from the security perspective, we presented three threat assumptions: (1) covert channels; (2) process fingerprinting side-channel; and (3) AES key recovery. The main takeaway of our work is an open problem of designing a randomized cache of comparable efficiency with modern set-associative LLCs, while still resisting both contention-based and occupancy-based attacks. This note is meant as an addendum to the main text in light of the observations made in [2]. To summarize, the authors in [2] argue that (1) L1d cache size plays a role in adversarial success, and that (2) a patched version of MIRAGE with randomized initial seeding of global eviction map prevents leakage of AES key. We discuss the same in this addendum.

翻译：在发表于USENIX Security 2025的主文本中，我们从性能与安全双重维度，系统分析了缓存占用率在随机化缓存设计考量中的作用。在性能层面，我们提出了一种统一的基准测试策略，实现了不同随机化缓存设计间的公平比较。相应地，从安全视角出发，我们构建了三种威胁假设：(1) 隐蔽信道；(2) 进程指纹侧信道；(3) AES密钥恢复攻击。本研究的核心结论指出了一个开放性问题：如何设计一种随机化缓存，使其在保持与现代组相联末级缓存相当效率的同时，仍能抵御基于资源竞争与基于占用率的双重攻击。本说明旨在结合文献[2]的观测结果，作为主文本的补充性论述。概括而言，文献[2]作者指出：(1) L1d缓存容量对攻击成功率存在影响；(2) 采用全局驱逐映射表随机化初始种子机制的MIRAGE修补版本可有效防止AES密钥泄漏。本补遗将就此展开讨论。