Data management apparatus, storage medium having stored therein data management program, storage medium having stored therein usage certificate data, and method of using data

2). A data management apparatus according to claim 1, wherein:

• said registration means registers the usage data included in the received data registration request in said storage means, in association with usage count information which indicates the number of times the usage data is permitted to be used;
• and
• when a usage count in the usage count information in said storage means which corresponds to the usage data regarding the received data usage request is less than or equal to a predetermined number, said providing means is prohibited from transmitting the usage data.

3). A data management apparatus according to one of claims 1 and 2, wherein:

• the usage certificate data further includes a network address for uniquely specifying the location of the apparatus on a network to which the apparatus is connected.

4). A data management apparatus according to any one of claims 1 to 3, wherein:

• the usage certificate data further includes a network address for uniquely specifying, on a network, the storage location of a program for transmitting the data usage request which includes the authentication information to the apparatus, the program being stored in the network.

5). A data management apparatus according to any one of claims 1 to 4, wherein:

• when a network address is included in the data registration request, said registration means transmits the usage certificate data to a destination specified by the network address, and, when no network address is included in the data registration request, said registration means transmits the usage certificate data to the sender of the data registration request,

6). A data management apparatus according to any one of claims 1 to 5, wherein:

• when a network address is included in the data usage request, said providing means transmits the usage data to a destination specified by the network address, and, when no network address is included in the data usage request, said providing means transmits the usage data to the sender of the data usage request.

8). A computer-readable storage medium having stored therein usage certificate data to be transmitted by a data management apparatus as set forth in claim 1, wherein:

• said computer-readable storage medium stores authentication information for authenticating, by said data management apparatus, whether or not a user is eligible to use the usage data and a network address for uniquely specifying, on a network, the storage location of a program for transmitting a data usage request which includes the authentication information to said data management apparatus, the program being stored in the network.

10). A method of using data according to claim 9, wherein:

• the provider further comprises:
• a registering step of registering the usage data in said storage means in association with usage count information which indicates the number of times the usage data is permitted to be used;
• and a prohibiting step of prohibiting transmission of the usage data when a usage count in the usage count information in said storage means which corresponds to the usage data regarding the received data usage request is less than or equal to a predetermined number.