Dr. Ninghui Li

Prof. Ninghui Li joined Purdue University in August 2003 as an Assistant Professor in Computer Science. His research interests are in computer security and applied cryptography, e.g., security and privacy in distributed systems, networks, databases, and electronic commerce, with a focus on access control. Professor Li received a Ph.D. in Computer Science from New York University in September 2000. Before joining Purdue, he was a research associate at Computer Science Department, Stanford University.

Prof. Li has worked extensively on trust management and automated trust negotiation, which are approaches to access control in decentralized, open, and distributed systems. In his Ph.D. thesis work, he designed and implemented Delegation Logic, a logic-based language for distributed authorization. While at Stanford, he has designed, together with Professors John Mitchell and Dr. Will Winsborough, the RT Role-based Trust-management framework, efficient goal-directed algorithms to do distributed credential chain discovery, logic-based semantic foundations for security policy languages, and algorithms and computational complexity characterization for analyzing properties of security policies such as safety and availability. Professor Li's recent research focuses on role-based access control, online privacy protection, access control policy specification and analysis, and operating system access control.