Privacy-preserving Crowd-sensing for Dynamic Spectrum Access

Dynamic spectrum access (DSA) is a well established paradigm which addresses the spectrum shortage caused by the rapid growth of connected wireless devices. In contrast to the legacy fixed spectrum allocation policies, DSA allows license-exempt users to access the licensed spectrum bands when not in use by their respective owners. While the database-driven DSA model is well suited for the TV white-space databases, other more fluid spectrum opportunities, such as the NOAA spectrum bands, remain exploreable only by either a solitary cyclostationary or multinodal cooperative signal detection and classification. While the multinodal, cooperative method offers improved signal detection and classification over solitary cyclostationary sensing, it does not provide any means of preserving the user's location privacy. Furthermore, both sensing methods suffer from very large delay due in part from the quiet periods they need to undergo in order to identify incumbent signal. To this end, we propose a location privacy-preserving crowd-sensing scheme for the DSA paradigm. Our proposed method provides location privacy for the crowd-sensing workers by leveraging the ElGamal cryptographic primitive, and it provides query obfuscation for the querying user through the $k{-}$anonymity paradigm. Through extensive experimentation, we show that our method is efficient for a realistic deployment.