A high-resolution side-channel attack on last-level cache

Abstract

Recently demonstrated side-channel attacks on shared Last Level Caches (LLCs) work under a number of constraints on both the system and the victim behavior that limit their applicability. This paper demonstrates on a real system a new high-resolution LLC side channel attack that relaxes some of these assumptions. Specifically, we introduce and exploit new techniques to achieve high-resolution tracking of the victim accesses to enable attacks on ciphers where critical events have a small cache footprint. We compare the quality of the side-channel in our attack to that obtained using Flush+ Reload attacks, which are significantly more precise but work only when the sensitive data is shared between the attacker and the victim. We show that our attack frequently obtains an equal quality channel, which we also confirmed by reconstructing the victim cryptographic key.