I have a number of books on all kinds of cryptography ... `classical' crypto, `Codes' [different from cyphers], number theory and so on.
While there are `better' books on specific parts of cryptology this book is by far the best overall introduction.
The title of this book scared me a bit. I have never been that `comfortable' with some sorts of maths and this book `sounded' brutal, and while it is a `math' book it is really not impossible to `figure out' [although some spots I must have read twenty times but thats the topic].
`REQUIRED BACKGROUND'
You can `do' with less but it helps to know basic algebra and understand variables. The vocabulary and nomenclature of areas as Set Theory and Probability [which I had to `study up' on] would be `nice' but you can `slide' without them,
Reading level: age 14 through senility :-) [ but a challenge for those `dead and encrypted'.`Classical', pen and paper, cryptology: B+Clear Writing: A- The `History' of cryptology: C+Physical [binding and paper, type, type size ... ] B
Also covered in detail is "public key' cryptography which as I wrote I do by `pre - written' computer program.
It covers the essential number theory required to understand various encryption schemes, and while it is a thin book, it doesn't omit any steps between various mathematical steps (" ... and then magic happens ..."). You end up with the satisfying feeling of being able to derive the proof for RSA, starting from high-school math.
Highly recommended.This is an introduction to the mathematics involved in the intriguing field of cryptology, the science of writing and reading secret messages which are designed to be read only by their intended recipients. It is written at an elementary level, suitable for beginning undergraduates, with careful explanations of all the concepts used. The basic branches of mathematics required, including number theory, abstract algebra and probability, are used to show how to encipher and decipher messages, and why this works, giving a practical as well as theoretical basis to the subject. Challenging computer programming exercises are also included. The book is written in an engaging style which will appeal to all, and also includes historical background on some of the founders of the subject. It will be of interest both to students wishing to learn cryptology per se, and also to those searching for practical applications of seemingly abstract mathematics.