Cryptanalysis of Reduced-Round DASH

In ACISP 2008, the hash family DASH has been proposed by Billet et al., which considers the design of Rijndael and RC6. DASH family has two variants that support 256-bit and 512-bit output length respectively. This paper presents the first third-party cryptanalysis of DASH-256 with a focus on the underlying block cipher A256. In particular, we study the distinguisher using differential and boomerang attack. As a result, we build a distinguishing attack for the compression function of DASH-256 with 8-round A256 using the differential cryptanalysis. Finally, we obtain a boomerang distinguisher of 9-round A256.