This book, which was first published in 1939, does not contain any recent ciphers. Aside from historic interest, readers will enjoy breaking quite complicated ciphers, on a level that requires no previous knowledge of cryptanalysis. In that sense, this is a follow-up book to Singh’s book [1]; students may enjoy Gaines’ book as a “play book.” This book always starts by explaining a cipher, and how it can be broken. An example illustrates each attack, and additional exercises, including solutions, are provided.

In the book’s 235 pages, both well-known ciphers, such as simple substitutions and Vignere, and not-so-well-known methods, such as those from Gronsfeld, Porta, or Kosiki, are covered. While the content is not taught in typical courses on computer security, the book provides enjoyable reading that requires a fair amount of thinking and problem solving skills (even though most of us will never need to manually break these ciphers).