Since I suck at math, I was a little intimidated by this book when I bought it almost ten years ago. I finally decided to pick it up and read it, only to discover a wonderfully approachable discussion of cryptography. The mathematically inclined will enjoy the book just as much as those of us who aren't so equipped. And for the latter, the math is presented in a way that even I was able to understand it. Cryptography can be a confusing topic, but Singh strung it together as one mystery after another. The book is packed with stories of actual uses which keep it engaging, and I quickly wanted more of the technical discussions just so that I could find out HOW one encryption system after another was created and then broken. There's also a great deal of actual history, that isn't accurately portrayed by modern media.

While Singh doesn't go into the details involved with how block and stream ciphers are currently used in modern data encryption, and doesn't discuss the various algorithms such as BLOWFISH, TWOFISH, AES, etc., overall he provides a wonderful overview on the core techniques used in encryption. After all, a symmetric cipher is a symmetric cypher, whatever the algorithm used, of which there are legion.