Matasano Crypto Challenges

Anyone done these before? Looks like fun, just sent the request e-mail. I'll try to report back!

We've built a collection of 48 exercises that demonstrate attacks on real-world crypto.

This is a different way to learn about crypto than taking a class or reading a book. We give you problems to solve. They're derived from weaknesses in real-world systems and modern cryptographic constructions. We give you enough info to learn about the underlying crypto concepts yourself. When you're finished, you'll not only have learned a good deal about how cryptosystems are built, but you'll also understand how they're attacked.
http://www.matasano.com/articles/crypto-challenges/

>>3
That's not it. If you finish the challenge[s] you should be able to discuss them, and share them publicly for others to learn from and attempt. From what >>2 and >>6 mention, it's as if they are using your answers to exhort actual people they break into their systems, instead of just giving you a known challenge to test with.

This pretty much says that they using your answers for exhortation:

There's no grading. We probably won't run your code (we'll definitely read it though).
Also if you can breeze through these we'd probably love to try to hire you. But don't worry: we're not recruiters and we're not jerks. (Incidentally, if you're interested in the kind of work we do, don't wait to get through the challenges to contact us.)