The ____ sublayer contains a header, computer (physical) addresses, error-detection codes, and control information.?

A service to solve the problem of minimizing the number of times that a user has to enter a password and the risk of an eavesdropper capturing the password and using it is known as the __________ .

A. authentication server B. ticket granting server C. Kerberos mutual authentication D. PCBC mode

The ____________________ key demotes a level, as when you want to add bullet points.

Fill in the blank(s) with the appropriate word(s).