Evolution of wireless sensor network security

The wireless sensor network's nodes are mostly distributed in the wild, and frequently in a state of unattended, therefore, the network vulnerable to various security threats. Under the condition of serious limitations in resources, the traditional network security system which needs to spend a lot of resources is no longer applicable. So, how to ensure the security of wireless sensor network under limited resources has become a key problem. This paper starts from the security features and targets of wireless sensor network, Summarizes the various threats for the wireless sensor network, and the main key management and security routing technologies, then make outlook for the future development.