If you're looking for lots of (mostly)good, free security training then check out https://www.cybrary.it. They have a class on cryptography and many on networking and networking devices, including CCNA-type training.
I'm not sure what they've got related to databases... seems to mostly be about SQL injections and whatnot. I don't know if that's what you want.
Cryptography is a particular interest of mine. Depending on how deep you want to go, maybe check out "Serious Cryptography" on No Starch Press, which is new and covers a lot of good stuff. Also, "Cryptography Engineering" and/or "Applied Cryptography", both by Schneier et al.