Ok, so this isn’t normally what I use this part of the site for, but I simply have to recommend the book \”Cryptonomicon\” by Neil Stephenson. I am 45% of the way through, and it is brilliant. It will even give you a grounding in cryptography, if you don’t already know it. (I found a \”simple\” crypto system I wrote myself a few years back, lovingly described, which dates from WWII!)
Read it, ten out of ten so far!
Update: It is a great book!