Patent ID: 8484470

Claim:
A peer-to-peer (P2P) type authentication system comprising: a plurality of node devices; wherein a first node device includes a unit for transmitting the authentication information thereof to a second node device, the second node device includes a unit for selecting a plurality of third node devices that are requested to verify the validity of the received authentication information, and a unit for transmitting the received authentication information to each of the selected plurality of third node devices, each of the third node device includes a unit for recording verification information that is used to verify the validity of the authentication information of the first node device, a unit for verifying the validity of the authentication information on the basis of the received authentication information and the recorded verification information, and a unit for transmitting the result information indicating the result of the verification to the second node device, and the second node device further includes a deriving unit for deriving weighted values indicating the reliability of the each verification of the plurality of third node devices and a unit for authenticating the first node device on the basis of the each result information and the each weighted value received from the plurality of third node devices, wherein any two of the node devices selected from the plurality of node devices communicate with each other.