Moinuddin Qureshi received the Best Paper Award at the 51st Annual IEEE/ACM International Symposium on Microarchitecture (IEEE MICRO), held October 19-24, 2018 in Fukuoka, Japan. Qureshi is a professor in the Georgia Tech School of Electrical and Computer Engineering (ECE), where he leads the Memory Systems Lab.
Qureshi was honored with this award for the paper, “CEASER: Mitigating Conflict-Based Cache Attacks via Encrypted-Address and Remapping.” Modern processors share the last-level cache between all the cores to efficiently utilize the cache space. Unfortunately, such sharing makes the cache vulnerable to attacks, whereby an adversary can infer the access pattern of a co-running application by carefully orchestrating evictions using cache conflicts.
Qureshi’s MICRO-2018 paper provided the key insight that we can efficiently defend against conflict-based attacks by accessing the cache with an encrypted address, as encryption would cause the lines that map to the same set of a conventional cache to get scattered to different sets. He and his team also proposed a design that periodically changes the encryption key and performs dynamic-remapping to improve robustness.
This design provides strong security that can tolerate years of attack, has low performance overhead of 1% slowdown, requires a storage overhead of less than 24 bytes for the newly added structures, and does not rely on any OS support. Such designs are vital in guarding against attacks such as Spectre and Meltdown that use cache side channels for covertly sending information.