Homework #1

Due: 9 a.m. in class 2/28.


1. Why does Manber's password strengthening scheme, described on
   page 89 of the course text, work?

2. Download the l0phtcrack utility. Using the program, find 3
   strong-looking passwords that l0phtcrack does not like. Then,
   find 3 passwords that l0phtcrack cannot break. For each of the
   passwords that it did not break, print out the amount of time
   the program spent trying. What is the variance in these times?
   Give an explanation of why the variance is the way it is.

3. What is a weakness in the way SFS pathnames (page 98) are
   described? How would you fix that?

4. What are the three most important points that are made by both
   the NSF and the Caltech/MIT study? Identify one area where the
   two reports appear to contradict each other, and give your opinion
   as to which one is right, and why.

5. What are the advantages of SSH over SSL for remote access?
   How do firewalls impact the choice of which protocol to use?

6. Describe the main differences between end to end security and
   link security.