Patent ID: 7136996

Claim:
A computer system including a business system and a commercial service system comprising: a terminal from which a user may send a request for use of the commercial service system to the business system when a user logs in to the business system; the business system including a password list having a plurality of passwords for users, and in response to the user request the business system checks authority for use of the commercial service system by the user, selects a password from the password list if the user has authority, and sends the password selected to the terminal; the commercial service system including financial information configured on the basis of the passwords sent from the business system, whereby the financial information includes a plurality of passwords different from each other to permit use of information in one account by a plurality of the users; wherein the terminal sends the selected password to the commercial service system; and the commercial service system compares the password from the terminal with a password previously provided, permits login if they match, and then designates the password as used and thereby prevent its subsequent reuse.