– Focuses on the creation of codes and ciphers. It details various encryption steps, including simple and polygraphic substitution, linear substitution, transposition, and polyalphabetic systems.
: The text is "spiced" with historical anecdotes and personal stories, particularly focusing on the first half of the 20th century. Decrypted Secrets
Excellent for those interested in the history of codemaking/breaking in the 20th century. – Focuses on the creation of codes and ciphers
as a first book. It assumes a "mathematical mindset" and familiarity with pure math terminology that may be inaccessible to casual readers. Researchers including simple and polygraphic substitution