Blockchain based secure IoT data sharing framework for SDN-enabled smart communities

Software-defined networks offer lower latency service and massive intelligent devices connectivity for the Internet of Things(IoT). As one of the pivotal applications in the IoT, smart community provides smart services for residents through the SDN technique. However, the centralized SDN suffers from single point of attacks such as DDoS from IoT devices and has the issue of data leakage. In this paper, we use blockchain and proxy re-encryption(PRE) technologies to tackle these challenges. The blockchain authorizes all devices in the network to improve their credibility and authenticity. What's more, a blockchain-based data sharing framework that combines a PRE scheme is introduced for secure device-to-device communication in smart communities. A series of smart contracts are designed for flexible operations of searching and updating records on the blockchain. The experiments reveal that our design is highly efficient and has high performance.