This paper introduces the Virtual Disk Integrity in Real Time (vDIRT) monitor, a mechanism to measure virtual hard disks in real time from the Dom0 trusted computing base. vDIRT is an improvement over traditional methods for auditing file integrity which rely on a service in a potentially compromised host. It also overcomes the limitations of existing methods for assuring disk integrity that are coarse grained and do not scale to large disks. vDIRT is a capability to measure disk reads and writes in real time, allowing for fine grained tracking of sectors within files, as well as the overall disk. The vDIRT implementation and its impact on performance is discussed to show that disk operation monitoring from Dom0 is practical.
JP Blake is a researcher at Assured Information Security in Rome, NY. His work focuses on trusted computing, Xen, and XenClient XT. Chris Rogers is a masters student at SUNY Binghamton.