New Attack on AES “Biclique Cryptanalysis of the Full AES,” by Andrey Bogdanov, Dmitry Khovratovich, and Christian Rechberger. Abstract. Since Rijndael was chosen as the Advanced Encryption Standard, improving upon 7-round attacks on the 128-bit key variant or upon 8-round attacks on the 192/256-bit key variants has been one of the most difficult challenges in the cryptanalysis of block ciphers fo