Abstract
Combining a fog layer to aggregate and process data for smart grids is a straightforward approach, yet it inevitably leads to trust issues and audition difficulty. Most existing data-sharing architectures did not consider the copious meter-fog communication and fog-cloud bulk data transmission simultaneously, or they relay the trustworthiness of the fog nodes on a single center. In this article, we design a meter-fog-cloud-blockchain data-sharing architecture for smart grids where the fog nodes are not only data relay stations but also semitrusted local data processing points, and the dual blockchains are responsible for device key management and data integrity audit, respectively. Moreover, a certificateless aggregate signcryption between fog and smart meters is designed, and the data sharing between servers is based on an authenticated key agreement mechanism to achieve optimal efficiency overall. Detailed security proofs are demonstrated and performance results show the practicality and efficiency of our data-sharing scheme.