I completed Introduction to Cryptography 1 (2012-003), the third offering in 2012.
I agree with all of the commenters. This is an extraordinary course and it sets a high bar for other course presenters. (Fortunately, this was my first course on Coursera and so finding lower-quality material since did not turn me away.)
In my case, I started the course twice before I completed it -- another advantage of the arrangement -- do-overs are perfectly acceptable.
What I noticed is that the second time I studied more that watched and read, and I was able to deepen some of the concepts, especially around security arguments and also the related number theory, so the second time was more rewarding than the first.
I attempted one of the programming exercises, but I fell far behind on that one and did not attempt any others.
Samples, when given, are generally in Python, and there are references to useful Python and C/C++ libraries to use in working some of the problems.
I want to be able to do the programming work but, for me, that was too much to deal with at one time.
I am registered for Introduction to Programming 2 starting in January. I knew this was coming and that added to my determination to finally get all the way through Part 1. Part 2 will get deeper into PKE, password-based authentication, and other more-recent topics that Dan Boneh and colleagues are keen on.