A secure framework for wireless sensor networks. The framework provides a system and method for providing network device authentication. The system and method comprises installing a unique device key in a network device and creating a chain of keys, wherein each subsequent key is encrypted using the previous key. The method executes an authentication process for storing and issuing keys, wherein the authentication process uses a unique device key to install a device site key in the network device and uses the device site key and the unique device key to authenticate the network device for communicating with a wireless network router, wherein the wireless network router creates a unique network-device-router key. The unique network-device-router key is used to authenticate the network device for communicating over the wireless network using an encrypted network session key and allows secure encrypted link-layer communications over the wireless network.