This is the archived website of SI 486H from the Spring 2016 semester. Feel free to browse around; you may also find more recent offerings at my teaching page.

Problem 95

Cryptographic voting

Due: May 3
Points: 4

Watch this video by researcher Ben Adida from 2007: https://youtu.be/ZDnShu5V99s

The whole video is interesting but a bit long; you can skip past the first 22 minutes or so (which is a bit about the history of voting and proposed improvements) if you want, although I think that's really interesting stuff. I'm really concerned with the technical description which begins around 22 minutes in, and really "gets into it" with the description of Scratch and Vote around minute 36.

For this problem, I want you to identify every instance you can find where randomness is used in this cryptographic voting scheme that the presenter is describing. For each instance, just give a brief (1 sentence) description of how randomness is being used.