Pretty cute little book about codes and ciphers. Lots of illustrations and examples for the reader to solve.
I am not sure it inspired "Cryptonomicon" by Neal Stephenson. But the fly leaf of "Cryptonomicon" shows a picture of young master Stephenson reading this book. I mean there is nothing about the enigma machine in this book.
Here is the centerfold of the book
It also has the dancing men code from Sherlock Holmes' The Adventure of the Dancing Men story. Not likely to be found new but prime for reprinting. ( )

This is the book which inspired that mind-blowing homage to the enigma machine "Cryptonomicon" by Neal Stephenson. I hope that at least one Epstein is alive to know this. ( )