A Formal Verification Methodology for Cache Architectures Based on Noninterference Hyperproperties

The design of secure cache architectures within computer systems primarily aims to mitigate side-channel attacks and minimize the risks of information leakage. However, verifying the effectiveness of secure cache designs introduces numerous challenges. The assessment of cache architecture security in prior research has mainly been based on the evaluators’ expertise, which lacks convincing evidence. Therefore, it is imperative to establish a universal and comprehensive formal verification methodology to evaluate the security of cache designs. This paper analyzes the advantages and disadvantages of an existing formal verification method. Based on this analysis, we introduce an enhanced formal verification method that utilizes noninterference hyperproperties to verify the security of cache architectures.In this paper, an extended triple mutual information formula is utilized to verify the satisfaction of noninterference hyperproperties within cache architectures and identify potential information leakages through three independence conditions. The degree of information leakage is evaluated by measuring the dependencies between the victim’s inputs and the attacker’s observations through triple mutual information. This paper instantiates existing cache architectures and reveals potential vulnerabilities by formalizing the behavior specification and replacement policy of a cache as an extended abstract state machine. Lastly, the cache security structure is formally validated utilizing the proposed security model, with the aim of evidencing its effectiveness and soundness.