P?ísp?vek ?ekého kryptologa Vlastimila Klímy - Útoky na šifru Hiji-bij-bij, který vzbudil zaslouženou pozornost na mezinárodním workshopu MKB byl p?ijat do archívu IACR (International Association for Cryptologic Research).
Cryptology ePrint Archive: Report 2005/003
Cryptanalysis of Hiji-bij-bij (HBB)
Abstract. In this paper, we show several known-plaintext attacks on the stream cipher HBB which was proposed recently at INDOCRYPT 2003. The cipher can operate either as a classical stream cipher (in the B mode) or as an asynchronous stream cipher (in the SS mode). In the case of the SS mode, we present known-plaintext attacks recovering 128-bit key with the complexity 2^66 and 256-bit key with the complexity 2^67. In the case of B mode with 256-bit key, we show a known-plaintext attack recovering the whole plaintext with the complexity 2^140. All attacks need only a small part of the plaintext to be known.
Category / Keywords. secret-key cryptography / cryptanalysis, Hiji-bij-bij, HBB, stream ciphers, synchronous cipher, asynchronous cipher, equivalent keys, known-plaintext attack
Date: received 5 Jan 2005