Abstract: The present invention relates to a content distribution server or the like, capable of more surely preventing an unauthorized use of a content. Content distribution servers 2 and 3 are arranged to be connectable via a telecommunication circuit to a user terminal device, and include: a distribution-content storing section 14 for storing a distribution content file composed of: content data; and a regulatory program including a first key for regulating reproducing the content data; a key storing section 15 for storing a second key which forms a pair with the first key; a key generating section 34 for generating, when receiving the terminal identification information transmitted from the user terminal device, a third key including the received terminal identification information and information of the second key; and transmitting controllers 16 and 34 for transmitting the third key to the user terminal device.

Abstract: The present invention relates to a content distribution server or the like, capable of more surely preventing an unauthorized use of a content. Content distribution servers 2 and 3 are arranged to be connectable via a telecommunication circuit to a user terminal device, and include: a distribution-content storing section 14 for storing a distribution content file composed of: content data; and a regulatory program including a first key for regulating reproducing the content data; a key storing section 15 for storing a second key which forms a pair with the first key; a key generating section 34 for generating, when receiving the terminal identification information transmitted from the user terminal device, a third key including the received terminal identification information and information of the second key; and transmitting controllers 16 and 34 for transmitting the third key to the user terminal device.

Abstract: The present apparatus offers a file data playback program that can restrict playback with certainty, without barring the communication of information to users, even if it is used for playback of files that are frequently played back and stopped repeatedly. This is the file data playback program for operating a computer as the playback means and playback stop means of file data. Playback is started from the position which the playback start position pointer 53 indicates. The apparatus has the processing which stops a playback and the processing which updates the playback start position pointer 53 in a playback stop position. The playback start position pointer 53 is updated.

Abstract: The apparatus offers a server for file distribution that can carry out playback of files attached to main files with certainty. The file distribution server includes a file data memory to store digital file data to distribute, which includes main file data and attached file data played back prior to main file data and digital file data in response to the request from user terminals. The management/playback program carries out the following processes: playing back distributed digital file data on the user terminal, controlling the prescribed operation in user terminal until playback of attached file data is completed.

Abstract: The apparatus includes a server for file distribution that can restrict the use of files within a certain limit and file distribution system therewith.

Abstract: The present invention offers a file distribution system that can restrict the use of files within a certain limit. The system includes a file distribution server. The file distribution server 2 is set up so that it can be connected with user terminals via communication network 3. The server 2 consists of several units. The units included are: the file data memory 24 to store digital file data to distribute, the program memory 25 to store a computer program to manage and play back digital file data, and the transfer-processing unit 26 to transfer management/playback program and digital file data in response to the request from user terminals.