COSC 511 Questions for March 15, 1999


1.  What is public-key (asymmetric) cryptography and how does it differ
from single-key (symmetric) cryptography?

2.  What application areas are best suited for single-key cryptography?
What are best suited for public-key cryptography?

3.  What is a digital signature and what is it used for?

4.  What is a digital certificate and what is it used for?

5.  What is a public-key infrastructure and what is it used for?

6.  If you are using single-key cryptography, how long (in bits) should
your key be so as to protect against a well-funded and highly motivated
adversary?  What if you are using public-key cryptography?

7.  What is a virtual private network (VPN) and what type of
cryptography is used?

8.  How does Pretty Good Privacy (PGP) work and what methods of
cryptography are used?

9.  How can the global positioning system be used to enhance information
security?

10.  What method of biometrics is best in terms of its ability to
discriminate between people?

11.  What is a watermark and what is it used for?