Privacy aware incentive mechanism to collect mobile data while preventing duplication

The recent technological advances in mobile devices such as smartphones foster a wide variety of emerging applications which consider users as the providers as well as consumers of the highly valuable real world data from the devices. Interestingly enough, many of the existing researches related to this topic implicitly assume that the users will actively provide mobile sensing data to enable the applications without any compensation, which is not necessarily true for many reasons, e.g. extend battery lifetime, improve system performance, etc., and thus many users are rather dormant in practice. Therefore, there is an urgent need to develop a proper incentive mechanism for the applications to transform the users to be more active so that the applications can collect much-needed high-quality data. One common key challenge to realize the incentive mechanisms is how to preserve the privacy of the users as they will be requested to provide possibly-privacy-invasive mobile data. An anonymous identity and pseudonym based scheme is a straightforward and easy-to-adopt solution to address this issue. Unfortunately, this approach makes it extremely difficult or inefficient to detect duplicated sensing data from greedy users hoping to get more incentive with the state-of-art strategies. The duplicate data can generate lots of noise when the respective application analyzes the data and will cause more cost to operate the application, and therefore is very harmful. This paper proposes a novel privacy-aware mobile incentive scheme of its kind without trusted third party (TTP) in the sense that two different messages, each of which is with the same sensing data, but with different pseudonym, from the same mobile user can be used to recover the private key of the user.