Abstract : A primary security challenge in such networks is the likelihood of node compromises caused by weak physical protection and hostile environments. As a result, key revocation is essential. In this talk, recent results on key revocation problems in mobile ad hoc networks (MANETs) will be presented. Two new fully self-organized key revocation schemes, which can be used in any pairing-based Identity Based Cryptography (IBC) scheme, adaptable to certificate revocation schemes in Public Key Infrastructure (PKI) solutions and secret key-based schemes in MANETs will be introduced. In the first scheme, nodes monitor their neighbors, securely propagate their observations, and revoke keys, once designed threshold accusations are received. The solution completely thwarts many attacks including Sybil, impersonation, and replay attacks. In the second scheme, the statistical Dirichlet multinomial model is introduced to key revocation processes. Each node keeps track of three categories of behavior, i.e., good, suspicious and malicious behavior. Differentiating between suspicious behavior and malicious behavior enables nodes to make multilevel responses by either revoking keys of malicious nodes or ceasing the communication with suspicious nodes for some time, to gather more information for making further decision.

Biography : Guang Gong received a B.S. degree in Mathematics in 1981, an M.S. degree in Applied Mathematics in 1985, and a Ph.D. degree in Electrical Engineering in 1990, from Universities in China. She received a Postdoctoral Fellowship from the Fondazione Ugo Bordoni, in Rome, Italy, and spent the following year there. After returning from Italy, she was promoted to an Associate Professor at the University of Electrical Science and Technology of China. During 1995-1998, Guang worked with several internationally recognized, outstanding coding experts and cryptographers, including Dr. Solomon W. Golomb, at the University of Southern California. Guang joined the University of Waterloo, ON. Canada in 1998, as an Associate Professor in the Dept. of Electrical and Computer Engineering in September 2000. She has been a full Professor since 2004. Dr. Gong’s research interests are in the areas of sequence design, cryptography, and communications security. She has authored or co-authored more than 180 technical papers and one book, co-authored with Dr. Golomb, entitled, ‘Signal Design for Good Correlation for Wireless Communication, Cryptography and Radar,’ published by Cambridge Press in 2005. Dr. Gong serves/served as Associate Editors for several journals including Associate Editor for Sequences for IEEE Transactions on Information Theory, and sat on a number of technical program committees and conferences. Dr. Gong has received several awards including the Best Paper Award from the Chinese Institute of Electronics in 1984, Outstanding Doctorate Faculty Award of Sichuan Province, China, in 1991 and the Premier’s Research Excellence Award, Ontario, Canada, in 2001.

Live webcast : http://vbxevents.powerstream.net/003/02484/Feb20/index.htm

Presentation slides : http://www.dss.uwaterloo.ca/presentations_files/2009_Guang_Gong.pdf