Codebook

Source: Wikipedia, the free encyclopedia.
U.S. State Department code book issued in 1899, an example of a one-part code, at the National Cryptologic Museum
Page 187 of the State Department 1899 code book, a one-part code with a choice of code word or numeric ciphertext. Numeric codes are prefixed by the page number.

A codebook is a type of document used for gathering and storing

books
, but today "codebook" is a byword for the complete record of a series of codes, regardless of physical format.

Cryptography

In

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 a codebook system was by Gabriele de Lavinde in 1379 working for the Antipope Clement VII.[1]

Two-part codebooks go back as least as far as

Antoine Rossignol in the 1800s.[1]

From the 15th century until the middle of the 19th century, nomenclators (named after nomenclator) were the most used cryptographic method.[2]

Codebooks with superencryption were the most used cryptographic method of World War I.[1]

The

JN-25
code used in World War II used 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.

Social sciences

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.

Data compression

Codebooks were also used in 19th- and 20th-century commercial codes for the non-cryptographic purpose of data compression.

Codebooks are used in relation to precoding and beamforming in mobile networks such as 5G and LTE. The usage is standardized by 3GPP, for example in the document TS 38.331, NR; Radio Resource Control (RRC); Protocol specification.

See also

References

  1. ^ a b c d Klaus Pommerening. "Codebooks".
  2. ^ Chris Christensen. "Codes and Nomenclators". p. 4