An Identity Privacy Preserving Incentivization Scheme for Participatory Sensing

Participatory sensing is a paradigm through which mobile device users (or participants) collect and share data about their environments. The data captured by participants is typically submitted to an intermediary (the service provider) who will build a service based upon this data. For a participatory sensing system to attract the data submissions it requires, its users often need to be incentivized. Such an incentivization mechanism typically requires users to at least partially disclose their identity to be able to reward them. This, however, might deter privacy conscious users from participating. Therefore, an incentivization mechanism needs to support anonymous data submission and rewarding. In addition, inference attacks can illegitimately gain further information about participants through linking data submissions or tracing rewards. This paper presents Identity Privacy Preserving Incentivization (IPPI), a decentralized peer-to-peer exchange that preserves identity privacy by enabling anonymous and unlinkable data submission and anonymous and untraceable reward allocation. This is achieved through the modification and extension of the concept of decentralized trading for cryptocurrencies to make payments (i.e., rewards) sent to a recipient (i.e., the participant) untraceable. Furthermore, the use of the Diffie-Hellman Exchange Protocol is modified to enable participants to create their own untraceable reward currency in the form of tokens to which the service provider can then assign value. The preservation of identity privacy is demonstrated by way of proof. The performance of the approach is also evaluated.