Wang Xiaoyun (1966- ) is a native of Zhucheng, Shandong Province. Wang is a crytographer. She received her bachelor's, master's, and doctor's degree in mathematics from Shandong University in 1987, 1990 and 1993 respectively. Currently, she is a professor of School of Mathematics and System Science, Shandong University. In 2005, she was engaged as "'Yang Zhenning' Chair Professor" by Tsinghua University. She is now a Distinguished Professor of Tsinghua University.

Wang is mainly engaged in cryptanalysis and the design of cryptographic algorithms. Since 1996, she has focused her research on hash functions and made world-shocking achievements by deciphering two hash functions MD5and SHA-1 which are internationally used in security system of computer. She brought up an original cryptanalysis theory on Hash Function and invented a series of techniques to find collections of Hash Functions, which included: utilizing Bit Tracing Method to search for collision paths of most hash functions efficiently, fulfilling Message Modification which improved efficiency of deciphering greatly, constructing an idea to combine near-collisions into collisions which was applied to break MD5 and SHA-1, converting an impossible differential of SHA-1 in first round into another complicated possible differential which results in possible differential path to break SHA-1, and exploring another kind of second pre-image attack on hash function MD4 which can be used to analyze MACs. By using her theory and techniques, MD5 and SHA-1 were successfully deciphered in 2004 and 2005 respectively, which attracted world-wide attention. She has published about 20 papers, 7 of which were on cryptanalysis of collisions attack of existing hash functions. Two standard publications in cryptography, Eurocrypto and Crypto, conferred Wang the Best Paper Award of 2005. She also won "Chinese Young Female Scientist Award" conferred by All-China Women's Federation, China Committee of United Nations Educational Scientific and Culture Organizations, China Association of Science and Technology, and L'Oreal (China) Company Limited.