Abstract: Based on measurement applications and its dynamic library to protect the integrity of the application of static credible, and analyzing the relation between interactive applications, this article established chain of trust of the transfer model , to protect applications running in the process of dynamic credible, to build reliable application environment. Based on the intransitive noninterference model, this article abstracted the system as applications, actions, states and outputs,and formally defined to run trusted applications. Application trusted theorem was verified formally. Furthermore, by associating application with system state, the definition and the theorem of application environment trusted were proposed.

Key words: Dynamic library, Chain of trust, Noninterference, Application environment