Reuse-trap: Re-purposing Cache Reuse Distance to Defend against Side Channel Leakage

Modern computing systems typically have multiple users sharing hardware resources. While such shared hardware have typically been performance boosters, they have also led to inadvertent side-effects such as side channels. Caches, that present the largest attack surface, have been popular among adversaries for side channel attacks. In this work, we repurpose a classic cache performance metric namely, reuse distance, to capture the activity of an adversary in cache timing channels. We design Reuse-trap, an efficient cache side channel mitigation framework to record reuse distances during victim accesses and carefully inject noise to mislead the spy from inferring the victim’s activity. Our experimental results show that we can identify adversaries with zero false positives and make timing channels suffer from over 50% bit error rate on average.