Block-D2D: Blockchain-enabled Cooperative D2D-assisted Fog Computing Scheme under Imperfect CSI

Fog computing (FC) supports cloud computing services at the edge of the device for more secure and reliable access and processing of the stored data. However, it is beneficial for time-sensitive applications, where the required delay is minimum, but not well suited for mission-critical applications, where the required delay is negligible. To fulfill this requirement, the authors worldwide started integrating FC with device-to-device (D2D) communication. But it was potentially affected by massive interference, which does not improve the total sum rate and secrecy capacity of the wireless channel. Motivated from these gaps, in this paper, we propose a blockchain-enabled cooperative D2D-assisted FC scheme under imperfect CSI in the presence of an eavesdropper called Block-D2D to enhance the total sum rate and secrecy capacity. We used non-orthogonal multiple access (NOMA) scheme for D2D pairs to improve the aforementioned characteristics. Still, the data on the device is not fully secure, which can be modified by any malicious user. This can be protected using blockchain technology, which is immutable, secure, and trusted. To improve the secrecy capacity of the network and spectral efficiency, we used a cooperative game theory. Simulation results show that the elevated performance of the NOMA-based Block-D2D scheme compared to the conventional OFDMA scheme in terms of sum rate, secrecy capacity, and system throughput.