Homework #15 - Censorship - Due Sunday Oct 23, 11PM


Turn in this assignment via email (vern@berkeley.edu) by the due date, with the term Homework in the Subject.

Read the paper Telex: Anticensorship in the Network Infrastructure, Eric Wustrow, Scott Wolchok, Ian Goldberg and J. Alex Halderman, USENIX Security 2011. Feel free to skip the Appendix. It's also fine to not try to assess the paper's cryptography, and just assume that it's correct, though you should understand the basic signalling mechanism in high-level terms. (Note that the TLS handshake shown in the paper differs a bit from the one covered in lecture, since here it's for a Diffie-Hellman key exchange, whereas lecture used an RSA-based key exchange.)

  1. 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.)

  2. Pick a censorship circumvention technology (or propose one of your own) and analyze it in terms of usability, performance, flexibility, vulnerability to censor counter-measures, and possible responses to those measures. (If you want to use Tor for the circumvention technology, that's fine, since while it was not designed for circumvention, that has become one of its important uses. But also feel free to pick a different technology.)