CompTIA Security+ Exam Prep

Answer: B - The Clark-Wilson Model security model separates data into one subset that needs to be highly protected and another subset that does not require a high level of protection. This is referred to as a constrained data item (CDI) and unconstrained data item (UDI). Users cannot modify critical data directly. Instead, the subject must be authenticated to a piece of software and the software procedures will carry out the operations on behalf of the user. The CDI must have its integrity protected by the transformation procedures (TPs). The UDI does not require such a high level of protection.