Wang Xiaoyun

Wang Xiaoyun (simplified Chinese: 王小云; traditional Chinese: 王小雲; pinyin: Wáng Xiǎoyún) (born 1966) is a researcher and professor in the Department of Mathematics and System Science, Shandong University, Shandong, China.

At the rump session of CRYPTO 2004, she and co-authors demonstrated collision attacks against MD5, SHA-0 and other related hash functions. (A collision occurs when two distinct messages result in the same hash function output). They received a standing ovation for their work.

In February 2005 it was reported that Wang and co-authors had found a method to find collisions in the SHA-1 hash function, which is used in many of today's mainstream security products. Their attack is estimated to require less than 2⁶⁹ operations, far fewer than the 2⁸⁰ operations previously thought needed to find a collision in SHA-1. Their work was published at the CRYPTO '05 conference. In August 2005, an improved attack on SHA-1, discovered by Xiaoyun Wang, Andrew Yao and Frances Yao, was announced at the CRYPTO conference rump session. The time complexity of the new attack is claimed to be 2⁶³.

Wang was born in Zhucheng, Shandong Province. She gained bachelor (1987), master (1990) and doctorate (1993) degrees at Shandong University, and subsequently lectured in the mathematics department from 1993. Her doctoral advisor was Pan Chengdong. Wang was appointed assistant professor in 1995, and full professor in 2001. She became the Chen Ning Yang Professor of the Center for Advanced Study, Tsinghua University in 2005.