PREFENDER: A Prefetching Defender against Cache Side Channel Attacks as A Pretender
Luyi Li1,a, Jiayi Huang2, Lang Feng1,b and Zhongfeng Wang1,c
1School of Electronic Science and Engineering, Nanjing University
aluyli@smail.nju.edu.cn
bflang@nju.edu.cn
czfwang@nju.edu.cn
2Department of Electrical and Computer Engineering, University of California, Santa Barbara
jyhuang@ucsb.edu
ABSTRACT
Cache side channel attacks are increasingly alarming in modern processors due to the recent emergence of Spectre and Meltdown attacks. A typical attack performs intentional cache access and manipulates cache states to leak secrets by observing the victim’s cache access patterns. Different countermeasures have been proposed to defend against both general and transient execution based attacks. Despite their effectiveness, they all trade some level of performance for security. In this paper, we seek an approach to enforcing security while maintaining performance. We leverage the insight that attackers need to access cache in order to manipulate and observe cache state changes for information leakage. Specifically, we propose PREFENDER, a secure prefetcher that learns and predicts attack-related accesses for prefetching the cachelines to simultaneously help security and performance. Our results show that PREFENDER is effective against several cache side channel attacks while maintaining or even improving performance for SPEC CPU2006 benchmarks.
Keywords: Security, Cache Side Channel Attacks, Prefetcher.
