Ben Adida has filmed an excellent presentation on verifiable voting systems given on the Google campus. It’s 92 minutes long. Check it out.
He also adds a few afterthoughts.
I really enjoyed the presentation. The first half is more understandable to a general audience. I particularly like that he uses the example of a public election that does not use a secret ballot to demonstrate that the problem of a verifiable election is basically trivial when a secret ballot is not required.
Ben is co-author of a sample end-to-end verifiable election system called ‘Scratch and Vote’.
All About Voting 