You can sign up for Cryptography courses at Coursera.org. You learn about basic tenets of crypto like attacker games, cryptogaphic advantage, cracking some expl

You can sign up for Cryptography courses at Coursera.org. You learn about basic tenets of crypto like attacker games, cryptogaphic advantage, cracking some exploits (AES-CBC). If you do the problem sets and programming assignments and pass the course without help, you are off to a very good start I would say.