Blockchain-assisted D2D Data Sharing in Fog Computing

In fog network, device-to-device (D2D) sharing is an important way to obtain data. However, due to an untrusted environment, it is difficult for a device to assess the reliability of the received data. What's more, devices may be reluctant to share data because of selfish, resulting in data supply and demand imbalances. In this regard, a data sharing scheme assisted by blockchain and matching algorithm is proposed. In order to ensure the authenticity of the data, the Bayesian inference model is employed to predict quality of the data, and a multi-factor data evaluation method is presented to make accurate judgments. Furthermore, different utility functions for data requesters and providers are defined, and a two-way matching game is introduced to balance of data supply and demand. To reduce the blockchain consensus delay and ensure the activeness of fog nodes, a practical byzantine fault tolerates (PBFT) consensus mechanism based on the frequency of interaction is investigated. The simulation results verify the effectiveness of the algorithm. The proposed data sharing scheme promotes the interaction of information in the fog computing network.