The Advanced Encryption Standard (AES), also called Rijndael, is a symmetric block-cipher with fixed 128-bit blocks and keysizes of 128, 192, or 256 bits. This algorithm is currently used by the U.S government for both classified and non-classified information, and has already phased out DES on all but legacy machines (triple DES is still authorized for government use, however). There were five finalists in the bid for the Advanced Encryption Standard, and the NSA analyzed all five and decreed them acceptable for encypting non-classified government documents, but Rijndael was eventually chosen for unspecified reasons, and later authorized for use on classified documents.
- Jeff Moser. "A Stick Figure Guide to the Advanced Encryption Standard (AES)". 2009.