A novel blockchain based framework to secure IoT-LLNs against routing attacks

Routing attacks in the Internet of Things environment (IoT) can result in degraded network performance and often denial of service. Low Power and Lossy Network (LLN) is that segment in IoT which comprises constrained devices like sensors and RFIDs. IPv6 Routing Protocol over Low Power and Lossy Networks (RPL) is the standard routing protocol proposed by IETF for routing in IoT-LLNs. RPL efficiently organizes and maintains the IoT-LLNs and also provides certain security features capable of countering external attacks. However, RPL is vulnerable to many insider attacks. In RPL supported IoT-LLNs, the control messages carry the LLN configuration information. The sensor nodes participating in the routing process are allowed to disseminate the configuration information to organize and maintain the LLNs. Two important configuration information carried in the control message, namely, the rank and the version number, play a major role in the topological formation of IoT-LLNs. A participating node may purposely advertise a false rank or version number information to instigate a routing attack. Such attacks degrade the performance of the IoT-LLNs and increase the consumption of network resources. In this paper, we propose a layered model of IoT routing security to analyze the vulnerabilities associated with each phase of the routing process. We explore how to leverage the inherent features of blockchain to enhance routing security in IoT-LLNs. To this end, we propose a blockchain-based framework with a smart contract for generating real-time alerts to efficiently identify the sensor nodes involved in the tampering of LLN configuration information.