There has been an increase in the electronic devices connected to the internet space, with at least 40 billion more devices becoming smart devices via the embedded system in 2020. The internet of things (IoT) is an emerging technology that deals with the interconnection of smart devices via the internet space, hence providing enhanced communication, interaction and service delivery. Communication between IoT devices take place over the internet, placing the internet at the heart of IoT applications, hence, extending the security challenges present in the traditional network into the IoT system. This dissertation describes the various layers of an IoT network, it made mention of the three-layer architecture and describes the functions of each of its component. Also, and more importantly, the security challenges that affects the layers of an IoT network and possible solutions for each layer were discusses. Furthermore, these items were combined in a stack to discuss on IoT platforms, which is a combination of IoT devices and services connected via a communication protocol and ensures applications are send to users in a secure system. This makes it possible for the continuity of security between different stages and data tracking between IoT devices. Issues rising from IoT platforms that make it difficult for integration with other IoT devices concludes this study.