/dā-tə in-krip-shən stan-dərd/ or /D-E-S/
the Data Encryption Standard, proposed in 1977 by the National Bureau of Standards (now NIST), with assistance from the National Security Agency. Based on the "Lucifer" cipher developed by Horst Feistel at IBM, DES is a secret key cryptosystem that cycles 64-bit blocks of data through multiple permutations with a 56-bit key controlling the routing. "Diffusion" and "confusion" are combined to form a cipher that has not yet been cryptanalyzed (see "DES, Security of"). DES is in use for interbank transfers, as a cipher inside of several RSA-based systems, and is available for PCs.