Internet of Things (IoT) plays a well-known role in the interconnection of the physical and virtual objects for the purpose of exchanging information. IoT environment can connect billions of devices or objects, each one has an ID for identification proof. The IoT system is considered one of the most important technologies in recent decades, and the focus of attention in many fields including healthcare, industry, agriculture, military applications, and space science. Thus, it is more attractive

more »

... for cyber-attacks. The IoT requires multi-dimensional security solutions such as confidentiality, integrity, and authentication services. In this paper, we address different security challenges, threats, and defenses in the layers of IoT systems. It is known that the IoT system architecture consists of three layers: physical/sensor layer, network layer, and application layer. To be comprehensive and to facilitate comparative methods, the security problems of each layer separately and the suggested solutions have been analyzed. Moreover, the challenges of the IoT especially big data and also the evaluation strategies of the IoT system and their effects on the security operations have been evaluated. Keywords Internet of things (IoT), Radio frequency identification (RFID), Big data analytics, Distributed denial of services (DDoS). Hassan I. Ahmed et al. 329 a) Sensing layer security requirements: The authentication, confidentiality and data encryption are essential to prevent illegal node access [15] . There are more challenges in sensing layer are: 1. The things are constrained in the Cost, size and energy consumption. 2.