Advanced Encryption Standard Rijndael <cryptography, algorithm> (AES) The {NIST}'s replacement for the {Data Encryption Standard} (DES). The Rijndael /rayn-dahl/ {symmetric block cipher}, designed by Joan Daemen and Vincent Rijmen, was chosen by a NIST contest to be AES. AES is Federal Information Processing Standard FIPS-197. AES currently supports 128, 192 and 256-bit keys and encryption blocks, but may be extended in multiples of 32 bits. (http://csrc.nist.gov/CryptoToolkit/aes/). Rijndael home page (http://esat.kuleuven.ac.be/~rijmen/rijndael/). (2003-07-04)