Data Encryption Standard (DES)


The Data Encryption Standard is a cipher that selected by NBS as an official Federal Information Processing Standard for the United States in 1976 and which has subsequently enjoyed widespread use internationally. It is based on a Symmetric-key algorithm that uses a 56-bit key. The algorithm was initially controversial with classified design elements, a relatively short key length, and suspicions about a National Security Agency backdoor. DES consequently came under intense academic scrutiny which motivated the modern understanding of block ciphers and their cryptanalysis.

DES was developed by IBM and was based upon IBM's earlier Lucifer cipher.
Source: Wikipedia