Deconstructing new cache designs for thwarting software cache-based side channel attacks

Abstract

Software cache-based side channel attacks present a serious tthreat to computer systems. Previously proposed countermeasures were either too costly for practical use or only effective against particular attacks. Thus, a recent work identified cache interferences in general as the root cause and proposed two new cache designs, namely partition-locked cache (PLcache) and random permutation cache(RPcache), to defeat cache-based side channel attacks by eliminating/obfuscating cache interferences. In this paper, we analyze these new cache designs and identify significant vulnerabilities and shortcomings of those new cache designs. We also propose possible solutions and improvements over the original new cache designs to overcome the identified shortcomings.