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Secure aggregation of users' privacy preferences in shared IoT environments

Internet of Things (IoT) technology has emerged as a core aspect of everyday life, since the number of deployed devices increases exponentially day by day. IoT offers the automation of many actions and strengthens the standard of societies' living. Despite the comfort and functionality it offers, it presents many risks, mainly related to security and privacy. Users have limited control on IoT devices that monitor their personal data, which poses significant concerns for their privacy. In this paper, we propose a system that focuses on users' privacy in a shared smart environment. It aims at enabling users that physically enter an installation equipped with IoT devices to control (i) whether smart devices monitor data, (ii) to which hosts such data are sent, and (iii) the allowed data detail (through traffic rate). This functionality is applied through monitoring users entering or leaving the smart environment, as their physical presence is detected through the use of fingerprint and motion sensors. To better enhance the privacy of users, their privacy preferences, with respect to the IoT devices operation, are homomorphically encrypted, while the encryption private key is stored on a separate secure component which is isolated from the rest of the network. A proof of concept of the proposed system has been implemented, using Raspberry Pi devices, to prove the validity of the solution and to assess the performance of the system.