Social network is a popular platform for users to exchange information. We consider how to allow a group of users such as a faculty union in a university to establish a secure channel. This is a group key agreement problem over a social network. However, different from the traditional setting, the connectivity of a social network can be arbitrary and a user is usually only aware of his neighbours. Especially, he does not even know the existence of other users. It is also unlikely for him to trust the public-key information of non-neighbours. This problem was not studied previously and existing group key agreement schemes are not suitable for our problem. In this talk, we present two efficient protocols for this problem with passive security. Our schemes approach the best known related schemes in all efficient measures (computation, communication and round complexity). One of our schemes also approximates the best possible round complexity. Finally, we show how to make our protocols actively secure.
Shaoquan Jiang received BS and MS degrees in applied mathematics from University of Science and Technology of China, and PhD degree in Electrical and Computer Engineering from University of Waterloo in 2005. His MS and PhD both focused on information security. He was a professor of school of computer science and engineering at University of Electronic Science and Technology of China, Chengdu, China from 2005 to 2013. Since 2013, he has been a professor of institute of information security at Mianyang Normal University, Mianyang, China. He also held visiting positions at University of Calgary (2006-2008) and at Nanyang Technological University (Singapore, 2008-2009). His research has been supported by highly competitive government grants: National Science Foundations of China (NSFC) and National 863 High Tech Development Plan. He served on the program committees of numerous international security conferences, was a publicity chair and a co-editor of ProvSec 2012 (Springer) and a guest editor of Security and Communication Networks (Wiley). He has published over 40 high quality peer-reviewed papers mostly at prestigious journals or conferences such as IEEE Trans. Inf. Theory, IEEE Trans. Dependable and Secure Computing, IEEE Trans. Inf. Forensics and Security, and ESORICS. His research interests include network security, secure protocols, physical-layer security, privacy, identity and message authentication, public-key encryption, and digital signatures.