A great article from Sophos Naked Security Blog. It is a must read to understand, yet another SSL vulnerability. You will also see why learning a bit more about crypto is necessary to understand such attack. It does bring the knowledge you learned in the Cryptography domain to good use.

This is a great book on Cryptography. A free copy can be downloaded at the link provided within this article. You are allowed to download one copy per person for personal usage.

This page has Peter's godzilla crypto tutorial, totalling 973 slides in 12 parts, of which the first 10 (+ part 0) are the tutorial itself and the 12th is extra material which covers crypto politics. Part 12 isn't officially part of the technical tutorial itself.

This is Domain 6 of the Security+ CBK. It is 11% of the exam.