Listmania!
Favourite Cryptography Books
Handbook of Applied Cryptography (Discrete Mathematics and Its Applications)Handbook of Applied Cryptography (Discrete Mathematics and Its Applications) by Alfred J. Menezes
Buy new: £36.73 / Used from: £20.00
Excellent reference, but I wouldn't start with this one
Cryptography Theory and Practice (Discrete Mathematics and Its Applications)Cryptography Theory and Practice (Discrete Mathematics and Its Applications) by Douglas R. Stinson
Buy new: £39.68 / Used from: £48.96
Perhaps the best textbook
Applied Cryptography: Protocols, Algorithms and Source Code in CApplied Cryptography: Protocols, Algorithms and Source Code in C by Bruce Schneier
Buy new: £26.54 / Used from: £15.03
Great collection what crypto can do; gives a nice overview
A Course in Number Theory and Cryptography (Graduate Texts in Mathematics)A Course in Number Theory and Cryptography (Graduate Texts in Mathematics) by Neal Koblitz
Buy new: £39.59 / Used from: £27.89
The math of crypto
Practical CryptographyPractical Cryptography by Niels Ferguson
Buy new: £21.89 / Used from: £24.49
Nice followup to Applied Cryptography
The Code Book: The Secret History of Codes and Code-breakingThe Code Book: The Secret History of Codes and Code-breaking by Simon Singh
Buy new: £5.97 / Used from: £0.37
Good, entertaining history