New models of cache architectures characterizing information leakage from cache side channels

Side-channel attacks try to breach confidentiality and retrieve critical secrets through the side channels. Cache memories are a potential source of information leakage through side-channel attacks, many of which have been proposed. Meanwhile, different cache architectures have also been proposed to defend against these attacks. However, there are currently no means for comparing and evaluating the effectiveness of different defense solutions against these attacks. In this paper, we propose a novel method to evaluate a system's vulnerability to side-channel attacks. We establish side-channel leakage models based on the non-interference property. Then we define how the security aspects of a cache architecture can be modeled as a finite-state machine (FSM) with state transitions that cause interference. We use mutual information to quantitatively reveal potential side-channel leakage of the architectures, and allow comparison of these architectures for their relative vulnerabilities to side-channel attacks. We use real attacks to validate our results.