Patent ID: 7315943

Claim:
An authentication system comprising a server system communicably connected to a communication terminal via a communication network, wherein a user handles the communication terminal to access data stored in the server system via the communication network, the server system comprising: a first authentication unit configured to receive user-identifying information from the communication terminal via the communication network, authenticate the user-identifying information, and generate first key information based on the authenticated user-identifying information, the first key information being transmitted to the user; a second authentication unit configured to receive the first key information from the communication terminal via the communication network, authenticate the first key information every time the first key information is received, and generate new second key information based on the same first key information every time the first key information is received, the new second key information generated each time entitling the user to access the data in the server system for a specified period of time as long as the communication terminal is activated, the second key information being transmitted to the communication terminal via the communication network; and an access permitting unit configured to receive the second key information from the communication terminal via the communication network and permit the user to access the data in the server system for the specified period of time every time the user accesses the server system.