Leveraging Homomorphic Encryption to Secure the Combinatorial Spectrum Auction without the Trustworthy Auctioneer

Spectrum auction is an enabling approach for drastically improving the spectrum utilization to satisfy the ever increasing service demands in wireless networks. However, the back-room dealing (i.e., the frauds of the untrustworthy auctioneer and the bid-rigging between the greedy bidders and the insincere auctioneer) makes these applications confront significant security challenges, and fails all existing secure auction designs to allocate spectrum bands considering the frequency reuse. In this paper, we propose a secure combinatorial spectrum auction (SCSA) by using homomorphic encryption to prevent the back-room dealing. The design of SCSA novelly incorporates cryptographic technique into spectrum auction to address the challenges of frauds and bid-rigging. It computes and reveals the results of spectrum auction while the actual bidding values of bidders are kept confidential. SCSA also provides a corresponding procedure for implementing the combinatorial spectrum auction with respect to interference constraints. Simulation results and analysis show that SCSA can effectively thwart the back-room dealing with limited communication and computational complexity, and achieve similar performance compared with existing spectrum auction designs in terms of spectrum utilization, the revenue of the auctioneer and the bidders’ satisfaction.