Internet of Things (IoT), an emerging network of physical objects, acts as catalyst for the future connected world. It is estimated that there will be around 50 billion connected objects by year 2020. An IoT enabled connected world improves the way human live and interact with surroundings. Through IoT valuable information and services are available to humans on demand and in real time. But these information and services may also cause harm at certain level if not thoroughly observed. With the advent of IoT, the future of the connected world will face new types of security threats since more than half of the total connected objects today are exposed to such threats and vulnerability and this number may increase as more devices are getting connected to internet. Security is the major concern in designing IoT systems since the data collected by IoT objects may be critical and also data transmitted and processed by overall IoT system may be sensitive and may lead to issues with safety, privacy, authorization and authenticity etc. Therefore while taking advantage of IoT we must also consider the ways, to the highest possible degree, to prevent the future IoT connected world from harming us. Cyber security in IoT deals with protecting connected objects for data authorization, authentication, tempering and losses as well as identifying potential risks to the system. This paper provides a brief review on how to adopt security practices in designing IoT systems to make them secure and safe.