Cryptanalysis

The copyright of the book is from 1939. So, enigma isn't studied. But for gaming is acceptable.

Remarkably clear intro into concealment , transposition and substitution ciphers.

No complicated maths either.

Definitely highly recommended for those interested in ciphers or even wanting a mild cerebral workout.

This book is a great introduction to classical cryptanalysis. Although it has a 1950s typeface, it is a very readable book. The main body of the book briefly covers concealment ciphers and then proceeds to a fuller exposition of transposition and substitution ciphers. Most chapters end with an opportunity to practice the skills learnt with ciphertext examples. Perhaps the most useful feature of the book are the tables of the most common letters, digrams and trigrams found in the English and various other European languages. It also contains other useful tables such as the most common first or last letters found in words of the English language. Conclusion: highly recommended.

A comprehensive and systematic introduction to the cryptanalysis of a large number of classical cryptosystems. This book is considered as the bible of the classical criptanalysis. It is also an extraordinary value. If you have a serious interest the cryptanalysis of classical cryptograms, you must read this book.