The Internet of Things (IoT) aims at connecting a large number of communication and information systems. With the further development of pervasive computing, these systems can be integrated into everyday objects, such as household devices and tools. When complex systems are interconnected, it is complicated to keep track of how secure a system or connection is and to distinguish which devices are connected within the IoT and which devices are not. As to the security, the IoT will be faced with more severe challenges. There are the following reasons: 1) the IoT extends the ‘internet' through the traditional internet, mobile network and sensor network and so on, 2) every ‘thing' will be connected to this ‘internet' and 3) these ‘things' will communicate with each other. Therefore, the new security and privacy problems will arise out of which authentication and access control are the most vital security issues that need to be taken care of. Therefore, we should pay more attention to the issues for confidentiality, authenticity and integrity of data in the IoT.