DAWG: A Defense Against Cache Timing Attacks in Speculative Execution Processors
Author(s)
Kiriansky, Vladimir L.(Vladimir Lubenov); Lebedev, Ilia A.; Amarasinghe, Saman P; Devadas, Srinivas; Emer, Joel S
DownloadAccepted version (429.0Kb)
Terms of use
Metadata
Show full item recordAbstract
Software side channel attacks have become a serious concern with the recent rash of attacks on speculative processor architectures. Most attacks that have been demonstrated exploit the cache tag state as their exfiltration channel. While many existing defense mechanisms that can be implemented solely in software have been proposed, these mechanisms appear to patch specific attacks, and can be circumvented. In this paper, we propose minimal modifications to hardware to defend against a broad class of attacks, including those based on speculation, with the goal of eliminating the entire attack surface associated with the cache state covert channel. We propose DAWG, Dynamically Allocated Way Guard, a generic mechanism for secure way partitioning of set associative structures including memory caches. DAWG endows a set associative structure with a notion of protection domains to provide strong isolation. When applied to a cache, unlike existing quality of service mechanisms such as Intel's Cache Allocation Technology (CAT), DAWG fully isolates hits, misses, and metadata updates across protection domains. We describe how DAWG can be implemented on a processor with minimal modifications to modern operating systems. We describe a non-interference property that is orthogonal to speculative execution and therefore argue that existing attacks such as Spectre Variant 1 and 2 will not work on a system equipped with DAWG. Finally, we evaluate the performance impact of DAWG on the cache subsystem.
Date issued
2018-12Department
Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory; Massachusetts Institute of Technology. Department of Electrical Engineering and Computer ScienceJournal
51st Annual IEEE/ACM International Symposium on Microarchitecture (MICRO)
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Citation
Kiriansky, Vladimir et al. "DAWG: A Defense Against Cache Timing Attacks in Speculative Execution Processors."51st Annual IEEE/ACM International Symposium on Microarchitecture (MICRO), October 2018, Institute of Electrical and Electronics Engineers (IEEE), December 2018 © 2018 IEEE
Version: Author's final manuscript
ISBN
9781538662403