IOT - things like the smart devices and sensors that connects and communicates through Internet. IOT applications like smart home, smart vehicles, smart retail, which makes the mankind’s life easier.  There is a prediction that we will be having million of devices connects to the Internet. Since the sensitive devices like baby monitoring devices,  health monitoring devices are the part of interconnected world there is the necessity to address the consequence of the security aspects of the IOT. The built-in nature of the IOT is to trace user’s identity easily, so the security and privacy concerns like stealing the data, disruption of operations and even the loss of life are becoming critical issues in today’s IOT applications.  Due to the resource constrained environment in IOT  the conventional algorithms is not enough to ensure the data security. So we need a less computational cost in terms of power consumption and memory management and more efficient cryptography algorithms which are discussed in this paper.