Security and privacy in the Internet of Things: threats and challenges

In the past few years, the Internet of Things (IoT) has emerged, grown and gradually affected the daily lives of human beings in many new application domains, ranging from wearable devices, smart manufacturing, to smart homes and ambient intelligence just to mention a few. However, realizing the full potential of IoT while ensuring user security and privacy remains an open research challenge. Existing security solutions and techniques are mainly conceived for centralized and distributed information systems and are not directly applicable to IoT-based systems. In fact, IoT systems have unconventional characteristics such as intermittent connectivity, high scalability, dynamic changes and limited resources and thus require a paradigm shift to develop innovative security and privacy solutions. In this survey, we firstly give an overview of security and privacy in IoT. After defining the context of IoT systems, we identify four main characteristics, which imply unprecedented threats and challenges to existing security solutions and techniques. From the perspective of these characteristics and IoT security requirements, we identify and elaborate specific threats and challenges related to the radio-frequency identification (RFID), wireless sensor networks (WSNs) and mobile delay tolerant networks (MDTNs), which are building blocks in many IoT-based systems. In addition, we discuss potential countermeasures to handle IoT threats and challenges.