Patent ID: 7660995

Claim:
An access control system comprising an application server and an authentication server which are connected to a terminal, wherein the authentication server includes: a reception unit for receiving a first identifier transmitted from the terminal, a transmission unit for transmitting a second identifier assigned dynamically to the terminal if an authentication by the first identifier is successful, and a memory for storing the first identifier and the second identifier while correlating them; the application server includes: a memory for storing the first identifier and a third identifier while correlating them, a reception unit for receiving the second identifier and the third identifier transmitted from the terminal, and a transmission unit for transmitting the first identifier stored in the memory corresponding to the third identifier to the authentication server if the authentication by the third identifier is successful; the authentication server reads out the second identifier corresponding to the first identifier received from the application server, from the memory of the authentication server and transmits it to the application server; and the application server transmits a packet reporting that the authentication has been successful to the terminal if the second identifier received from the authentication server coincides with the second identifier received from the terminal.