Editing Block cipher (section)

===Rijndael / AES===
{{Main|Advanced Encryption Standard}}
The ''Rijndael'' cipher developed by Belgian cryptographers, [[Joan Daemen]] and [[Vincent Rijmen]] was one of the competing designs to replace DES. It won the [[Advanced Encryption Standard process|5-year public competition]] to become the AES (Advanced Encryption Standard).

Adopted by NIST in 2001, AES has a fixed block size of 128 bits and a key size of 128, 192, or 256 bits, whereas Rijndael can be specified with block and key sizes in any multiple of 32 bits, with a minimum of 128 bits. The block size has a maximum of 256 bits, but the key size has no theoretical maximum. AES operates on a 4×4 [[column-major order]] matrix of bytes, termed the ''state'' (versions of Rijndael with a larger block size have additional columns in the state).