Abstract The Internet of Things (IoT) paradigm is one of the most exciting innovations of recent years. However, with each connected object the number of possible attacks will increase exponentially. This article presents a comparative study between the different solutions against Iot attacks, we will first present a security architecture that can be divided into 3 main layers: perception layer, network layer, and application layer. Each layer is divided by hierarchies that allow us to guarantee security, i.e. confidentiality, integrity, authenticity, and data acquisition. We then focused on the attacks of the perception layer which is extremely vulnerable to security attacks while classifying these attacks according to the two wireless technologies (WSN, RFID). Finally, we discuss the different approaches provided against these attacks.