The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography is a book by Simon Singh, published in 1999 by Fourth Estate and Doubleday. The Code Book describes some illustrative highlights in the history of cryptography, drawn from both of its principal branches, codes and ciphers. Thus the book's title should not be misconstrued as suggesting that the book deals only with codes, and not with ciphers; or that the book is in fact a codebook.