We first address an important drawback of prior work, namely the lack of consideration of collusion attacks that are highly relevant for such multi-user settings. We explain why existing security models are insufficient and why previous protocols become insecure in the presence of colluding parties. We remedy this problem by providing new security and privacy definitions that guarantee meaningful forms of collusion resistance. We propose new collusion-resistant participatory sensing protocols satisfying our definitions: a generic construction that uses anonymous identity-based encryption (IBE) and its practical instantiation based on the Boneh-Franklin IBE scheme.
We then extend the functionality of participatory sensing by adding the ability to perform aggregation on the data submitted by the users, without sacrificing their privacy. We realize this through an additively-homomorphic IBE scheme which in turn is constructed by slightly modifying the Boneh-Franklin IBE scheme. From a practical point of view, the resulting scheme is suitable for calculations with small sensor readings/values such as temperature measurements, noise levels, or prices, which is sufficient for many applications of participatory sensing.Category / Keywords: applications / privacy, participatory sensing, collusion resistance, data aggregation, additively homomorphic identity-based encryption Original Publication (with major differences): 13th International Conference on Cryptology and Network Security (CANS 2014) Date: received 28 May 2014, last revised 11 Sep 2014 Contact author: guenther at cs tu-darmstadt de Available format(s): PDF | BibTeX Citation Version: 20140912:050732 (All versions of this report) Discussion forum: Show discussion | Start new discussion