Providing secure input to a system with a high-assurance execution environment

Methods for maintaining the security of a secured execution environment on a system comprising said secured execution environment and a second execution environment are disclosed. A maintained current state for the secured execution environment is selected from among a group of possible states including a standard input mode state and a nexus input mode state. A flow of user input is directed according to the current state through a secure kernel of both the second environment and the secured execution environment.