The Advanced Encryption Standard (AES) is the dominant algorithm used to encrypt sensitive data. Also known by its original name Rijandeal, AES is a symmetric block cipher, or one that uses the same key for encryption and decryption.
AES is sanctioned by the US Government’s National Institute of Standards and Technology (NIST), which announced AES as U.S. FIPS PUB 197 (FIPS 197) on November 26, 2001.
AES had undergone that agency’s five-year open competition over the years 1997-2000 to replace the Data Encryption Standard (DES), which was being deprecated in the face of adversaries’ growing brute-force attack capability. Fifteen (15) data encryption designs competed in the process, including notables such as Twofish, before the Rijndael cipher was ultimately selected as the winner.
On May 26, 2002, AES came into force as a federal government standard and today is the first (and only) publicly accessible cipher approved by the U.S. National Security Agency (NSA) for top secret information when used in an NSA approved cryptographic module.
"If you're looking to encrypt sensitive data, you'll find that AES provides flexibility and ease of implementation across all systems. AES is also open-source and rated for classified information, so you have excellent security without the limits of a proprietary algorithm."