Slide attacks

Abstract

It is a general belief among the designers of block-ciphers that even a relatively weak cipher may become very strong if its number of rounds is made very large. In this paper we describe a new gene- ric known- (or sometimes chosen-) plaintext attack on product ciphers, which we call the slide attack and which in many cases is independent of the number of rounds of a cipher. We illustrate the power of this new tool by giving practical attacks on several recently designed ciphers: TREYFER, WAKE-ROFB, and variants of DES and Blowfish.