Patent ID: 8848912

Claim:
An authentication method used in communication between a server and a terminal, comprising: holding, at the server and the terminal, a hash function and authentication information in common; acquiring, at the server and the terminal, a communication parameter which is temporarily common during the communication between the server and the terminal as an authenticating communication parameter; generating, at the server and the terminal, an authentication key using the hash function based on the authentication information and the authenticating communication parameter; and carrying out, at least at one of the server and the terminal, authentication between the server and the terminal using the authentication key which has been generated, wherein the communication parameter which is temporarily common during the communication is a communication parameter which is for establishment of a communication channel, which is necessary for the terminal to connect to a wireless base station, and which is set in a process that is carried out every time communication is made between the terminal and the wireless base station regardless of whether authentication is done or not, the authenticating communication parameter is changed during transmission of the authentication key and the authenticating communication parameter is stored in the terminal and the wireless base station, a communication parameter which is periodically notified from the wireless base station to the terminal is used as the authenticating communication parameter, the authenticating communication parameter is already shared by the terminal and the wireless base station prior to the authentication, and the authenticating communication parameter is at least one of: an identifier which is used to identify a link established between the terminal and the wireless base station and which changes every time the link is reestablished; and a number which is given to a unit of transmission and reception of data and which changes every time transmission and reception of data is performed.