On the Implementation of the Attack against the Signature Scheme SFLASH(Application)

Abstract

In 2001, SFLASH, which is one of the most efficient signature schemes, was proposed by Patarin et al. This scheme is a kind of multivariate quadratic public-key cryptosystems and has an efficient implementation on smart cards. Moreover, NESSIE selected SFLASH as one of the recommended schemes in 2003. In 2007, however, Dubois et al. proposed an efficient attack against SFLASH. On the other hand, the explicit algorithm would not be clearly shown. In this paper, we explicitly describe the algorithm by Dubois et al. Furthermore, we give some experimental results of the attack under the most general situation, and also discuss the results.