1. The Mechanism by which a person using a terminal can communicate directly with the trusted computing base (TCB. ) Trusted path can only be activated by the person or the TCB and cannot be imitated by untrusted software. 2. A mechanism by which a user can communicate directly with a trusted function. Example: A trusted path is required when a user changes his password. 3. A mechanism by which a person at a terminal can communicate directly with the Trusted Computing Base. This mechanism can only be activated by the person or the Trusted Computing Base and cannot be imitated by untrusted software.