The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography

The 56-bit version of Feistel’s Lucifer cipher was officially adopted on November 23, 1976, and was called the Data Encryption Standard (DES). A quarter of a century later, DES remains America’s official standard for encryption.

A cipher is the name given to any form of cryptographic substitution in which each letter is replaced by another letter or symbol.

Secret communication achieved by hiding the existence of a message is known as steganography, derived from the Greek words steganos, meaning “covered,” and graphein, meaning “to write.”

A nomenclator is a system of encryption that relies on a cipher alphabet, which is used to encrypt the majority of a message, and a limited list of codewords.

In fact, Britain had captured thousands of Enigma machines, and distributed them among its former colonies, who believed that the cipher was as secure as it had seemed to the Germans. The British did nothing to disabuse them of this belief, and routinely deciphered their secret communications in the years that followed.

Cryptanalysis could not be invented until a civilization had reached a sufficiently sophisticated level of scholarship in several disciplines, including mathematics, statistics and linguistics. The Muslim civilization provided an ideal cradle for cryptanalysis, because Islam demands justice in all spheres of human activity, and achieving this requi

In America there are no restrictions on key size, but U.S. software companies are still not allowed to export Web products that offer strong encryption. Hence, browsers exported to the rest of the world can handle only short keys, and thus offer only moderate security. In fact, if Alice is in London buying a book from a company in Chicago, her Inte

The Swiss experiment with optic fibers demonstrates that it would be feasible to build a system that permits secure communication between financial institutions within a single city.

For example, the hotline between the presidents of Russia and America is secured via a onetime pad cipher.