Joan Daemen (; born 1965) is a Belgian cryptographer who co-designed the Rijndael cipher with Vincent Rijmen, which was selected as the Advanced Encryption Standard (AES) in 2001. More recently, he co-designed the Keccak cryptographic hash, which was selected as the new SHA-3 hash by NIST in October 2012. He has also designed or co-designed the MMB, Square, SHARK, NOEKEON,  3-Way, and BaseKing block ciphers.