Have you tried Matasano Crypto Challenges? Here's a good review from the PinBoard Blog:
I mentioned earlier that I thought every web programmer should try
their hand at these. It is very illuminating to look at your own web
app from the vantage point of an attacker actually writing code. At
the very least, you will never be confused about cipher block modes
again, or have to worry that someone will ask you to explain how a
public key works in an interview. And there is a whole slew of dumb
mistakes you will now avoid (replacing them with smarter mistakes that
will become the subject matter of challenges 48-96).
Also, Cody Brocious from Accuvan LABS AppSec Team is running the Breaker 101 course:
The majority of the coursework will be styled as a CTF (capture the
flag). In essence, you will be breaking from day one and putting these
attacks in practice. The exceptions are some of the crypto and the
secure architecture/threat modeling portions of the course. These will
be graded for your benefit but do not count towards your score.
Exams are largely practical as well, but will be more open-ended, as
you will see in real-world security testing.