Using SDN and blockchain-based trust evaluation for automated risk management in the Internet of Things

The Internet of Things (IoT) carries a big promise. One of the most widely known use cases tells the story about a refrigerator that notices that you are running out of milk and places an order to the local supermarket. This story captures the true spirit of IoT in which different "things" from different manufactures talk to each other and also interact with an outside entity (the supermarket). However, with the advent of the IoT home networks may host more and more devices of questionable security and privacy thus making the IoT still look like a utopia. Indeed, due to the lack of updates, low-price points or mere lack of interest from vendors, weakly secured connected devices have become targets of choice for numerous exploits resulting in focused or larger scale attacks, from command and control to large botnets like the recent Mirai attacks. In our approach, we rely on the blockchain technology as a trusted source of information among untrusted devices. In our blockchain-based solution intelligent network managers monitor and report on devices' behaviors as compared to a declared baseline describing devices' expected behavior. In this solution we leverage analyzers accessing such a crowd-sourced blockchain-based information source to assess devices' rogueliness likelihood, based on their history or on the history of similar devices. The result is a trust assessment framework that intelligent network managers can leverage to predict attacks or vulnerabilities affecting their managed devices and react by (dis)connecting such devices from the network.