The following items will test your grasp of the material covered in this lesson. There is only one correct answer
for each item. When you complete the exercise check your answers with the answer key that follows. If you
answer any item incorrectly, study again that part of the lesson which contains the portion involved.
What does the term key mean?
The system of physical restraints to unauthorized entry or access
The sequence of randomly-generated binary bits used for encrypting or decrypting signals
The cipher lock system used for facility access
Signal operation instructions
What are the four major types of COMSEC keys?
Sargent/Greenleaf, American, Master, and Dibold
One-time pad, signal operation instructions (SOI), Communications-Electronics Operation
Instructions (CEOI), and standing operating procedures (SOP)
Traffic encryption, traffic decryption, key encryption, and key decryption
What is FOUO?
A protective marking for information for official use only (not for public disclosure)
A classification marking for material which, if disclosed, could cause serious harm to national
A classification marking for information for official use only (not for public disclosure)
An obsolete administrative marking