This fantastic book is a brilliant introduction to cryptography, complete with concise and simple explanations covering transposition and substitution ciphers, codes, and their solutions. Contained within this book are more than 150 cryptographic problems providing practical applications as well of tests of ingenuity ¿ a must-have for any aspiring cryptographer. As well as showing a detailed history of cryptography throughout the years, this effective book gets the reader solving problems with various cryptographic methods, starting simply and progressing to tasks of incredible complexity. Clear and concise, this book is a definitive introduction to the field and deserves a place in any cryptographic library. Originally published in 1955, this scarce book is proudly republished now with an introductory biography of the author.