Network sales system

A network-based sales system, comprising:

• at least one buyer computer for operation by a user desiring to buy a product;
• at least one merchant computer;
• and
• at least one payment computer;
• said buyer computer, said merchant computer, and said payment computer being interconnected by a computer network;
• said buyer computer being programmed to receive a user request for purchasing a product, and to cause a payment URL to be sent to said payment computer that comprises a product identifier identifying said product, a payment amount, and a payment URL authenticator comprising a cryptographic function of contents of said payment URL based on a cryptographic key;
• said payment computer being programmed to receive said payment URL, to verify said payment URL authenticator to ensure that said payment URL authenticator was created using said cryptographic key, to ensure that said user has sufficient funds or credit to cover said payment amount, to identify said merchant computer operated by said merchant willing to sell said product to said buyer, to cause an access URL to be created that comprises said product identifier and an access URL authenticator comprising a cryptographic function of contents of said access URL based on a cryptographic key, and to cause said access URL to be sent to said buyer computer;
• said buyer computer being programmed to cause said access URL received from said payment computer to be sent to said merchant computer;
• and
• said merchant computer being programmed to receive said access URL, to verify said access URL authenticator to ensure that said access URL authenticator was created using said cryptographic key, and to cause said product to be sent to said user desiring to buy said product.

A method of operating a payment computer in a computer network comprising at least one buyer computer for operation by a user desiring to buy a product, at least one merchant computer, and at least one payment computer, the method comprising the steps of:

• receiving, at said payment computer, a payment message that said buyer computer has caused to be sent to said payment computer in response to a user request for purchasing a product, said payment message comprising a product identifier identifying said product;
• causing an access message to be created that comprises said product identifier and an access message authenticator based on a cryptographic key;
• and
• causing said access message to be sent to said merchant computer, said merchant computer being programmed to receive said access message, to verify said access message authenticator to ensure that said access message authenticator was created using said cryptographic key, and to cause said product to be sent to said user desiring to buy said product.

A network-based sales system, comprising:

• at least one buyer computer for operation by a user desiring to buy products;
• at least one shopping cart computer;
• and
• a shopping cart database connected to said shopping cart computer;
• said buyer computer and said shopping cart computer being interconnected by a computer network;
• said buyer computer being programmed to receive a plurality of requests from a user to add a plurality of respective products to a shopping cart in said shopping cart database, and, in response to said requests to add said products, to send a plurality of respective shopping cart messages to said shopping cart computer each of which comprises a product identifier identifying one of said plurality of products;
• said shopping cart computer being programmed to receive said plurality of shopping cart messages, to modify said shopping cart in said shopping cart database to reflect said plurality of requests to add said plurality of products to said shopping cart, and to cause a payment message associated with said shopping cart to be created;
• and
• said buyer computer being programmed to receive a request from said user to purchase said plurality of products added to said shopping cart and to cause said payment message to be activated to initiate a payment transaction for said plurality of products added to said shopping cart;
• said shopping cart being a stored representation of a collection of products, said shopping cart database being a database of stored representations of collections of products, and said shopping cart computer being a computer that modifies said stored representations of collections of products in said database.

A method of operating a shopping cart computer in a computer network comprising at least one buyer computer for operation by a user desiring to buy products, at least one shopping cart computer, and a shopping cart database connected to said shopping cart computer, said method comprising the steps of:

• receiving, at said shopping cart computer, a plurality of shopping cart messages sent to said shopping cart computer by said buyer computer in response to receipt of a plurality of requests from a user to add a plurality of respective products to a shopping cart in said shopping cart database, each of said shopping cart messages comprising a product identifier identifying one of said plurality of products;
• modifying said shopping cart in said shopping cart database to reflect said plurality of requests to add said plurality of products to said shopping cart;
• and
• causing a payment message associated with said shopping cart to be created;
• said buyer computer being programmed to receive a request from said user to purchase said plurality of products added to said shopping cart and to cause said payment message to be activated to initiate a payment transaction for said plurality of products added to said shopping cart;
• said shopping cart being a stored representation of a collection of products, said shopping cart database being a database of stored representations of collections of products, and said shopping cart computer being a computer that modifies said stored representations of collections of products in said database.

A network-based link message system, comprising:

• at least one client computer for operation by a client user;
• and
• at least one server computer for operation by a server user;
• said client computer and said server computer being interconnected by a computer network;
• said client computer being programmed to send an initial link message to said server computer;
• said server computer being programmed to receive said initial link message from said client computer, to create, based on information contained in said initial link message, a session link message that encodes a state of interaction between said client computer and said server computer, said session link message comprising a session link authenticator, computed by a cryptographic function of said session link contents, for authenticating said session link message, and to cause said session link message to be sent to said client computer;
• said client computer being programmed to cause said session link message to be sent to a computer in said network that is programmed to authenticate said session link message by examining said session link authenticator and that is programmed to respond to said session link message based on said state of said interaction between said client computer and said server computer.

A method of operating a server computer in a network-based link message system comprising at least one client computer for operation by a client user and at least one server computer for operation by a server user, said client computer and said server computer being interconnected by a computer network, said method comprising the steps of:

• receiving, at said server computer, an initial link message sent to said server computer by said client computer;
• creating, based on information contained in said initial link message, a session link message that encodes a state of interaction between said client computer and said server computer, said session link message comprising a session link authenticator, computed by a cryptographic function of said session link contents, for authenticating said session link message;
• and
• causing said session link message to be sent to said client computer;
• said client computer being programmed to cause said session link message to be sent to a computer in said network that is programmed to authenticate said session link message by examining said session link authenticator and that is programmed to respond to said session link message based on said state of said interaction between said client computer and said server computer.