Columbia subject headings:
Computers--Access control--United States.
Data encryption (Computer science)--United States.
Export controls--United States.
Harvard subject headings:
Computer security--United States
Computers--Access control--United States.
Data encryption (Computer science)--United States.
Export controls--United States.
National security--United States
Princeton subject headings:
Computers--Access control--United States.
Data encryption (Computer science)--United States.
Export controls--United States.