Trusted computing base (TCB)

The combination of hardware, software, and controls that form a trusted base that enforces your security policy. The totality of protection mechanisms within a computer system, including hardware, software, and communications equipment, the combination of which is responsible for enforcing a security policy. A TCB consists of one or more components that together enforce a unified security policy over a product or system. The ability of a trusted computing base to correctly enforce a security policy depends solely on the mechanisms within the TCB and on the correct input by system administrative personnel of parameters (such as a user’s clearance) related to the security policy. Totality of protection mechanisms within a computer system, including hardware, firmware, and software, the combination responsible for enforcing a security policy.