Abstract: A method of distributing an advertisement is capable of reliably producing a sales promotion effect for commodities carried on the advertisement. A consumer uses a terminal to download contents data from a contents server in step S1. A banner advertisement image is transmitted from a coupon management server to the terminal in step S2. The terminal displays contents and a banner advertisement on its display screen. Thereafter, the consumer uses the terminal to access a shop Web site server, and acquires contents data including a commodity list in step S3. The coupon management server transmits coupon information to the terminal in step S4. The terminal displays the commodity list and the coupon information on the display screen. When settling information is transmitted from the terminal to the coupon management server, the coupon management server carries out a settling process.

Abstract: The present invention relates to a system wherein each of a reservation server that makes reservations of sales and purchases, a portable terminal owned by a user who makes a reservation, and a shop terminal provided in stores where goods are sold, and a service or entertainment is provided, is connected to a communication network whereby the user makes a reservation for sales or purchase by accessing the reservation server, the reservation server encrypts contents of the sales/purchase reservation and transmits the encrypted reservation information to the aforementioned portable terminal, the user presents the transmitted encrypted reservation information to the shop terminal, visiting the shop terminal, and the shop terminal accesses the reservation server to confirm whether the presented encrypted reservation information is legitimate or not and admits the presenter of the encrypted reservation information if the reservation information is legitimate.

Abstract: The above-described objects of the present invention are achieved by, in an authentication system for authenticating users who are parties to a transaction, an authentication method includes the steps of (a) supplying a first user with a matching key for a prospective transaction, (b) receiving at a second user the matching key supplied to the first user; and (c) matching the key supplied from the first user to the second user against the key supplied to the first user, after the second user has received the key from the first user.