To whom correspondence should be addressed. E-mail: yantaoli@foxmail.com, liyantao@live.com Received on May6, 2010 Li Yantao, is a Ph.D. candidate in College of Computer Science at Chongqing University, China. He received his M. S. degree in Computer Science in December, 2009 and B. S. degree in Mathematics in June, 2007. From September 2010 to September 2012, he is a visiting Ph.D student supported by China Scholarship Council (CSC) at Department of Computer Science in the College of William and Mary, USA. His research area includes hash function construction, wireless sensor network and cellular neural network.