Internet of things (IoT) could be found on everywhere in today live. It is used in smart cities like roads, hospitals and in smart homes like controlling door or air conditioner unit or preventing fires and much more. These devices that use IoT are connected to the internet and send and receive many of important data through the network. This open the attacker’s starvation to invade the IoT networks and got its valuable data. The problem with the IoT devices is the limited performance components that make it difficult to apply the existing security method on it. This limitation requires a need to present lightweight algorithms which support the IoT devices. The survey in this paper reviewed several proposed algorithms and authentication methods in IoT to stop many kinds of attacks with considering the limitation of the IoT system. © 2019 IEEE.