Abstract: An authentication system that uses personal variable biometric information which changes according to times and environments, and an authentication method using the same are disclosed. The variable biometric information-based authentication system includes: a mobile terminal configured to generate information regarding an ID that intends to access a facility or information requiring an access authority, and to collect variable biometric information, such that information regarding the ID and the variable biometric information are stored all together; and a variable biometric information management server configured to, when the mobile terminal requests a login command regarding the ID, verify validity of the login command regarding the ID based on the variable biometric information.

Abstract: A complex authentication system that uses personal variable biometric information which changes according to times and environments, and a complex authentication method using the same are disclosed. The variable biometric information-based complex authentication system includes: a mobile terminal configured to collect variable biometric information; a variable biometric information management server configured to store the variable biometric information received from the mobile terminal; and an agent server configured to, when the mobile terminal requests a login command regarding the ID, verify validity of the login command regarding the ID based on the variable biometric information.

Abstract: Provided herein is a variable social network service method and apparatus. The variable social network service method includes receiving, by a variable social network service apparatus, information on whether or not a user serves as a bridge from a user apparatus of the user, and determining, by the variable social network service apparatus, whether or not to expand a social network based on the user based on the information on whether or not the user serves as the bridge, wherein the variable social network service apparatus determines whether or not social networking is possible between a first network subject of the user and a second network subject of the user depending on whether or not the user serves as the bridge.