A codebook is a type of document used for gathering and storing cryptography codes . Originally, codebooks were often literally books , but today "codebook" is a byword for the complete record of a series of codes, regardless of physical format.
6-518: Acme Commodity and Phrase Code is a codebook providing the general-purpose commercial telegraph code known as the Acme Code . It was published in 1923 by the Acme Code Company. The book provides a listing of condensed terms and codes used to shorten telegrams and save money. The book was extremely popular amongst businesses in the 1930s. This code was one of the few telegram codes permitted by
12-524: A codebook of 30,000 code groups superencrypted with 30,000 random additives. The book used in a book cipher or the book used in a running key cipher can be any book shared by sender and receiver and is different from a cryptographic codebook. In social sciences, a codebook is a document containing a list of the codes used in a set of data to refer to variables and their values, for example locations, occupations, or clinical diagnoses. Codebooks were also used in 19th- and 20th-century commercial codes for
18-574: A codebook system was by Gabriele de Lavinde in 1379 working for the Antipope Clement VII . Two-part codebooks go back as least as far as Antoine Rossignol in the 1800s. From the 15th century until the middle of the 19th century, nomenclators (named after nomenclator ) were the most used cryptographic method. Codebooks with superencryption were the most used cryptographic method of World War I. The JN-25 code used in World War II used
24-594: The Allied powers during the Second World War. The Acme code consists of one hundred thousand five letter codes each intended to stand in for a phrase. It was designed to be tolerant of transposition errors ; the author claims that "no transposition of any two adjoining letters will make another word in the book". However, as later discovered by J. Reeds, the code did not provide this level of error correction, containing at least eleven pairs of words differing only by
30-517: The codebook must be available at either end. The distribution and physical security of codebooks presents a special difficulty in the use of codes compared to the secret information used in ciphers , the key , which is typically much shorter. The United States National Security Agency documents sometimes use codebook to refer to block ciphers ; compare their use of combiner-type algorithm to refer to stream ciphers . Codebooks come in two forms, one-part or two-part: The earliest known use of
36-501: The transposition of two letters. Despite these errors, this code is a precursor to more modern error correction codes . This cryptography-related article is a stub . You can help Misplaced Pages by expanding it . Codebook In cryptography , a codebook is a document used for implementing a code . A codebook contains a lookup table for coding and decoding; each word or phrase has one or more strings which replace it. To decipher messages written in code, corresponding copies of
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