Yiqun Lisa Yin (Chinese: 殷益群; pinyin: Yīn Yìqún) is a Chinese-American cryptographer and independent security consultant.
Yin is known for breaking the SHA-1 cryptographic hash function, for developing the RC6 block cipher, and for her service as editor of the IEEE P1363 project for the standardization of public-key cryptography.
Yin was a student at Peking University from 1985 to 1989, and earned a bachelor's degree in applied mathematics there.
[4] With Ron Rivest, Matt Robshaw, and Ray Sidney, she was one of the designers of RC6, a block cipher with symmetric keys that was one of five finalists for the 1997–2000 Advanced Encryption Standard competition.
[5] In 2005, with Wang Xiaoyun and Hongbo Yu, Yin demonstrated an unexpected high probability of collisions (two different data values with the same hash) in the SHA-1 cryptographic hash function, originally designed by the National Security Agency.