Which of the following can be used as a covert channel? 

Answer options:

A. Storage and timing.
B. Storage and low bits.
C. Storage and permissions.
D. Storage and classification.

A

The Orange book requires protection against two types of covert channels, Timing and Storage. The following answers are incorrect: Storage and low bits. Is incorrect because, low bits would not be considered a covert channel. Storage and permissions. Is incorrect because, permissions would not be considered a covert channel. Storage and classification. Is incorrect because, classification would not be considered a covert channel.