Cryptography I by Dan Boneh (Stanford University): https://www.coursera.org/course/crypto

The videos are probably available for download somewhere else, so you don't have to wait. Someone posted a site here on HN that saved all the coursera videos, but I can't remember the name.

Each video lasts ~20 min if I remember correctly, but they are very intensive. I never wanted to watch more than one or two per day, my mind would have blown.