Utilizing blockchains in opportunistic networks for integrity and confidentiality

Opportunistic networks (OppNets) are usually a set of smart, wearable, and portable devices or entities with mobility that connect wirelessly without requiring infrastructure. Such a network is of great importance in data transmission, particularly in incidents and disasters, whether man-made or natural. However, message integrity and confidentiality are of concern when dealing with vital and physiological data transmission under strict privacy regulations. In this work, we propose a structure to classify messages based on their priority in different queues. Furthermore, due to the decentralized architecture of OppNets, we propose a blockchain-based structure for providing security for high-priority messages. It contains three sequences of functional blocks with a light and simplified implementation that make it suitable for battery-powered wearable devices that are limited in energy consumption and computational units. The simulation results show that by increasing the number of nodes in the network, the average of the changes in block sizes is neglectable, which addresses the computation bottleneck. Furthermore, we analyze the performance of the proposed structure in terms of message delivery and network overhead compared with the Epidemic and Prophet routing algorithms. These results indicate advancing the overall performance of the proposed algorithm.