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.