AES is an acronym for Advanced Encryption Standard and is a symmetrical block cipher. It was adopted as a US government standard in 2001 (FIPS 197) and has since then been widely spread. It was developed by two Belgian cryptographers, Daemen and Rijmen who submitted it to the AES selection process under the name "Rijndael". AES today is not exactly the same as Rijndael, but close to. AES can use 128, 192 or 256 bits key length and is considered extremely secure.