Improved Preimage Attacks on RIPEMD-160 and HAS-160

• Published in: KSII transactions on Internet and information systems 2018, 12(2), , pp.727-746
• Main Authors: Yanzhao Shen, Gaoli Wang
• Format: Article
• Language: English
• Subjects: 컴퓨터학
• ISSN: 1976-7277; 1976-7277
• DOI: 10.3837/tiis.2018.02.011

The hash function RIPEMD-160 is a worldwide ISO/IEC standard and the hash function HAS-160 is the Korean hash standard and is widely used in Korea. On the basis of differential meet-in-the-middle attack and biclique technique, a preimage attack on 34-step RIPEMD-160 with message padding and a pseudo-preimage attack on 71-step HAS-160 without message padding are proposed. The former is the first preimage attack from the first step, the latter increases the best pseudo-preimage attack from the first step by 5 steps. Furthermore, we locate the linear spaces in another message words and exchange the bicliques construction process and the mask vector search process. A preimage attack on 35-step RIPEMD-160 and a preimage attack on 71-step HAS-160 are presented. Both of the attacks are from the intermediate step and satisfy the message padding. They improve the best preimage attacks from the intermediate step on step-reduced RIPEMD-160 and HAS-160 by 4 and 3 steps respectively. As far as we know, they are the best preimage and pseudo-preimage attacks on step-reduced RIPEMD-160 and HAS-160 respectively in terms of number of steps. KCI Citation Count: 0