Patent ID: 8346668

Claim:
An electronic money transaction system, comprising: a management server; a verification server; a remittance terminal; and a reception terminal, wherein, in response to a request from said remittance terminal, said management server issues an inactive electronic certificate to which a use limit amount is set and notifies said verification server of a certificate ID included in said inactive electronic certificate, wherein said remittance terminal obtains said inactive electronic certificate from said management server and generates an active electronic certificate usable for settlement through allocating a money amount equal to or less than said use limit amount to said inactive electronic certificate and activating said inactive electronic certificate by giving a group signature, wherein said reception terminal verifies said active electronic certificate obtained from said remittance terminal based on said group signature, wherein said verification server matches the certificate ID notified from said management server with the certificate ID included in the active electronic certificate verified by said reception terminal to verify availability of said active electronic certificate, wherein the remittance terminal is preliminarily registered in a group, obtains a member key unique to the remittance terminal and carries out said group signature by using the member key, wherein the reception terminal verifies said group signature by using a group public key preliminarily obtained from the management server, and wherein at least one of the management server, the verification server, the remittance terminal, and the reception terminal is implemented using a computer.