Blockchain for smart cities: applications for IoT and video surveillance systems

The recent revolution of the Internet of Things introduces new engaging operat- ing scenarios. The IoT paradigm enables the intertwined use of physical and soft- ware components through the interconnection of devices that exchange data with each other without direct human interaction in several fields, especially in industrial and home environments. In the framework of the Italian-Vietnamese cooperation on the topics of smart cities and Blockchain, we present two applications of the blockchain technology, which can be applied, respectively in indoor, for monitoring and controlling smart homes, and in outdoor, for visual monitoring through video surveillance systems. In both cases, we propose decentralised architectures that aim at solving common IoT problems and vulnerabilities, with a specific focus on pri- vacy issues. The introduced flexibility, extensibility and security in indoor IoT en- vironments and outdoor video surveillance systems permit to foresee smarter cities that assist citizens with innovative services both in indoor and outdoor environ- ments. We propose a reinterpretation of the role of the IoT gateway, making it blockchain-aware and handling IoT transactions without a central trusted authority. As for video surveillance, we focus on two different directions. First, we provide the capability to analyse multiple video-flows from different cameras deployed around the city by heterogeneous owners, guaranteeing the integrity of the timestamps and camera settings. Second, the system ensures that the positions of cameras, their orientation and their mechanical parameters are not physically ma- nipulated; otherwise, the platform generates a warning. We guarantee citizens' pri- vacy monitoring and tracking camera settings and storing video flows. The absence of digital and physical manipulations guarantees citizens against possible violations of their privacy. To face these risks, we introduce a blockchain-based video surveil- lance system that jointly provides validation and immutability to camera settings and surveillance videos, making them readily available to authorised users in case of events and paving the way to new distributed city-wide monitoring systems.