Joint optimization of energy consumption and network latency in blockchain-enabled fog computing networks

Fog computing is considered as a solution to accommodate the emergence of booming requirements from a large variety of resource-limited Internet of Things (IoT) devices. To ensure the security of private data, in this paper, we introduce a blockchain-enabled three-layer device-fog-cloud heterogeneous network. A reputation model is proposed to update the credibility of the fog nodes (FN), which is used to select blockchain nodes (BN) from FNs to participate in the consensus process. According to the Rivest-Shamir-Adleman (RSA) encryption algorithm applied to the blockchain system, FNs could verify the identity of the node through its public key to avoid malicious attacks. Additionally, to reduce the computation complexity of the consensus algorithms and the network overhead, we propose a dynamic offloading and resource allocation (DORA) algorithm and a reputation-based democratic byzantine fault tolerant (R-DBFT) algorithm to optimize the offloading decisions and decrease the number of BNs in the consensus algorithm while ensuring the network security. Simulation results demonstrate that the proposed algorithm could efficiently reduce the network overhead, and obtain a considerable performance improvement compared to the related algorithms in the previous literature.