Outsourcing Scheme of ABE Encryption and its Implementation and Evaluation

Dr. Go Ohtake
ICT 618B
Friday, August 12, 2016 - 14:00

Abstract:  Integrated broadcast-broadband services allow viewers to simultaneously receive broadcast content over the airwaves and additional information related to the content over the Internet. These services can be enriched and personalized by using viewers' personal information such as viewing history. This, however, requires viewers to share their viewing history with service providers, hence raising privacy concerns. Using attribute-based encryption (ABE) one can empower viewers to share their viewing history with service providers who satisfy certain criteria (e.g. have well-established reputation). ABE systems require computation that may not be affordable by less resourceful clients. To reduce this computation, in this paper we propose an outsourcing scheme for ABE encryption. Our work is the first to consider security against a malicious cloud server that does not follow the protocol and may collude with other entities in the system. We motivate and introduce the required security notions that guarantee correctness of the outsourced operation and privacy of the viewers' personal information, and prove the security of our scheme in the proposed model. We implement our scheme and show that the encryption cost of a user terminal can be dramatically reduced compared to that by using the conventional ABE system.

Bio:  Dr. Go Ohtake received B.E. and M.E. degrees from Tokyo Institute of Technology in 1999 and 2001, respectively. He joined NHK (Japan Broadcasting Corporation) in 2001 and received a Ph.D. degree from the Institute of Information Security in 2009. He was a visiting researcher at University of Calgary from December 2014 to November 2015. He is a research engineer of NHK Science and Technology Research Laboratories. His research interests include public key cryptography, and its application for copyright protection and privacy preserving.