SwitchBlade : Policy-Driven Disk Segmentation

As it becomes more common for multiple operating systems to run machines to run on a single machine, strict isolation mechanisms have become increasingly critical. While OS-level isolation protects against some attacks, all OS protections can be subverted by directly accessing a shared disk. In this paper, we introduce SwitchBlade, a disk protection model that confines operating systems stored on the same disk into segments. Users physically insert policy-carrying tokens into the drive to access specific segments. Without the capability to access an OS segment, it is fully isolated from the user. We implemented SwitchBlade on a real prototype. We describe our architecture and implementation, and comment on the user experience and tools we have developed to work with the system. We provide a security analysis showing SwitchBlade’s resistance to attack and evaluate its performance on real systems – the disk can realistically boot in about 8 seconds with our current prototype. We thus can provide the isolation guarantees equivalent to physically separate systems without the enormous usability burdens such systems entail.