Advanced Encryption Standard (AES), also called Rijndael (its original name) is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. Advanced Encryption Standard is based on the Rijndael cipher developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen, who submitted a proposal to NIST during the algorithms selection process. Rijndael is a family of ciphers with different cipher key and block sizes. AES has been accepted by the U.S. government and is now used worldwide. It supersedes the Data Encryption Standard (DES), which was published in 1977. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data.
In the US, AES was announced by the NIST as U.S. FIPS PUB 197on November 26, 2001. This announcement followed a five-year standardization process in which fifteen competing designs were presented and evaluated, before the Rijndael cipher was selected as the most suitable algorithm. AES became effective as a federal government standard on May 26, 2002 after approval by the Secretary of Commerce. AES is also included in the ISO/IEC 18033-3 standard. AES is available in many different encryption packages, and is the first and only publicly accessible cipher approved by the National Security Agency (NSA) for top secret information.