Efficient transitive trust model for mobile terminal

Based on the theory of Trusted Computing Group (TCG), trust is extended from Trusted Computing Base (TCB) to Operating System (OS) and applications. But the efficient trust chain is required during boot and whole system running time. This paper describes a transitive trust model for mobile terminal. We propose a static trust chain by locating boot-code and OS image into TCB, which is more safety, reliability and efficiency than the trust structure of TCG. After boot, resources are protected by Trusted Agents (TA). Based on this mechanism, dynamic trust chain is proposed. Only the processes granted trust property by TA could access specific resources. The authors have also developed a prototype of trusted mobile terminal system. System booting time is shortened by 5.2s. The experiment results of files and network accessing indicate that the proposed model may cause system performance decrease between 0.1% and 16%. The presented model can be applied to build a high efficiency trusted mobile terminal.