A trusted path is a protected channel that assures the secrecy and authenticity of data transfers between a user's input/output (I/O) device and a program trusted by that user. We argue that, despite its incontestable necessity, current commodity systems do not support trusted path with any significant assurance. This paper presents a hypervisor-based design that enables a trusted path to bypass an untrusted operating-system, applications, and I/O devices, with a minimal Trusted Computing Base (TCB). We also suggest concrete I/O architectural changes that will simplify future trusted-path system design. Our system enables users to verify the states and configurations of one or more trusted-paths using a simple, secret-less, hand-held device. We implement a simple user-oriented trusted path as a case study.
Zhou et al. REF uses a microhypervisor to build a verifiable trusted path between I/O devices and applications, assuring secrecy and authenticity on x86 systems.
Building Verifiable Trusted Path on Commodity x86 Computers
2012 IEEE Symposium on Security and Privacy
2012 IEEE Symposium on Security and Privacy
Computer Science