trusted computing base (TCB)

The trusted computing base (TCB) is everything in a computing system that provides a secure environment. This includes the operating system and its provided security mechanisms, hardware, physical locations, network hardware and software, and prescribed procedures. Typically, there are provisions for controlling access, providing authorization to specific resources, supporting user authentication, guarding against viruses and other forms of system infiltration, and backup of data. It is assumed that the trusted computing base has been or should be tested or verified.