University Honors

Covert and side channel attacks are an emerging class of dangerous cybersecurity attacks.These attacks exploit the sharing of resources between two different processes when theyexecute on the same system and share hardware or software resources. Applications are protectedfrom direct access to each other’s state by hardware and operating system protections but can useobservable delays when they use shared resources to communicate (covert channels) or spy oneach other (side channels). In this paper, we focus on a new type of covert and side channelattacks that exploits the Linux virtual file system (VFS). We start by showing how the syncfssystem call can lead to observable differences in timing, and how these differences can beexploited to build covert and side channel attacks. We target the file system wide disksynchronization mechanism in the syncfs system call and explore the time difference whenflushing the dirty pages in the page cache. The covert channel attack is built based on whetherthere are dirty pages that can be flushed. Besides that, we further explore the opportunity of sidechannel attack and construct a website fingerprinting attack and a video fingerprinting attack.