Which of the following is the lowest TCSEC class where in the system must protected against
covert storage channels (but not necessarily covert timing channels)?

A.
B2

B.
B1

C.
B3

D.
A1

Explanation:
The B2 class referenced in the orange book is the formal security policy model
based on device labels that can use DAC (Discretionary access controls) and MAC (Mandatory
Access Controls). It provides functionality about covert channel control. It does not require covert
timing channels. You can review the B2 section of the Orange Book.