Lecture Notes in Computer Science vol:1636 pages:81-94
FSE 1999 date:March 24-26, 1999
In the first part of this paper the decorrelation theory of Vaudenay is analysed. It is shown that the theory behind the proposed constructions does not guarantee security against state-of-the-art differential attacks. In the second part of this paper the proposed Decorrelated Fast Cipher (DFC), a candidate for the Advanced Encryption Standard, is analysed. It is argued that the cipher does not obtain provable security against a differential attack. Also, an attack on DFC reduced to 6 rounds is given.