Cryptanalysis of SOBER-t32

Abstract. Sober-t32 is a candidate stream cipher in the NESSIE competition. Some new attacks are presented in this paper. A Guess and Determine attack is mounted against Sober-t32 without the decimation of the key stream by the so-called stuttering phase. Also, two distinguishing attacks are mounted against full Sober-t32. These attacks are not practically feasible, but they are theoretically more efficient than exhaustive key search.

• Type: Conference
• Year: 2003
• Where: FSE
• Authors: Steve Babbage, Christophe De Cannière, Joseph Lano, Bart Preneel, Joos Vandewalle
• Keywords: Candidate Stream Cipher, Cryptography, Exhaustive Key Search, FSE 2003, So-called Stuttering Phase