Homework #2 - Traceback - Due Monday Jan 27, 1PM

Read the paper Practical Network Support for IP Traceback, Stefan Savage, David Wetherall, Anna Karlin and Tom Anderson, SIGCOMM 2000.

Note, the second half of section 5.1 gets somewhat hairy in a technical sense. You don't need to grasp all of the details, but you should strive to understand the gist of the discussion. (You also don't need to worry about understanding where the analytic expressions come from.)

Briefly write up your views of:

1. What are the main contributions of this paper?
2. What parts of the paper do you find unclear? (optional)
3. What parts of the paper are questionable? (That is, you think a conclusion may be wrong, an approach or evaluation technically flawed, or data ill-presented.)
4. The paper is somewhat fast-and-loose in its discussion of one of the scheme's significant limitations. State what you think it is, explain why the explanation is not satisfactory, and discuss how to reasonably extend the scheme to deal with the limitation (if you think that's viable), or why the limitation appears quite difficult to address.
5. Discuss another form of spoofed identity that occurs in the Internet and sketch a mechanism to either prevent it or trace it back. Briefly discuss your proposed approach in terms of what it costs, its limitations, and how an attacker might subvert it.

Keep in mind the homework logistics framed in Homework #1.