Iot device authenticated based on dynamically reconfigurable puf and server and method for authenticating the same

An authentication server for authenticating an Internet of Thing (IoT) device, comprising:

• a database in which authentication-related data about at least one IoT device being pre-registered is stored;
• and
• a processor functionally connected to the database, wherein the processor
• receives, from a first IoT device, a first response value, a pseudo identity, and a first random number, wherein the first response value is generated and encrypted from a first challenge value being selected through a weak physical unclonable function (WPUF) of the first IoT device for an authentication request,
• obtains a first response value, a second challenge value, a second response value, and a session key corresponding to the received pseudo identity, among the authentication-related data,
• authenticates the first IoT device by comparing the obtained first response value with the received first response value based on the obtained session key, and
• updates authentication-related data comprising the second challenge value and the second response value for a next session by using a reconfigurable physical unclonable function (RPUF) of the first IoT device.

An Internet of Thing (IoT) authentication method based on a physical unclonable function (PUF) by an IoT device, comprising:

• generating a first response value corresponding to a first challenge value by using a weak physical unclonable function (WPUF);
• generating a current session key based on the first response value and then transmitting the current session key to an authentication server in relation to a first random number;
• receiving some of a pre-registered challenge-response pair (CRP), and a second random number from the authentication server, wherein the some of the CRP and the second random number are transmitted as a result of authentication based on the first random number and the session key by the authentication server;
• authenticating the authentication server based on the session key, the some of the CRP, and the second random number;
• generating a second response value corresponding to a second challenge value, among the some of the CRP, using a reconfigurable physical unclonable function (RPUF);
• and
• authenticating the authentication server by comparing the second response value with the some of the CRP and then updating the session key and the CRP for a next session.