Patent ID: 8412939

Claim:
An apparatus of a second sink for authenticating a node in a sensor network, the apparatus comprising: a memory for storing node authentication information; and a processor configured to: send a request for the node authentication information to a first sink, when receiving a re-authentication request from the node; receive the node authentication information from the first sink; re-authenticate the node based on the node authentication information, periodically create a second neighboring sink list including information on at least one adjacent sink neighboring the second sink, and determine if a node-authenticable sink exists in the second neighboring sink list, check a common adjacent sink included in both a first neighboring sink list including information on at least one adjacent sink neighboring the first sink and the second neighboring sink list by comparing the first neighboring sink list and the second neighboring sink list, when the node-authenticable sink does not exist in the second neighboring sink list, and send a request for the re-authentication of the node to the checked common adjacent sink while transmitting the second neighboring sink list to the checked common adjacent sink.