Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices. Server side data transfer devices and client side data transfer devices can be provided in multiple-to-one, one-to-multiple, or multiple-to-multiple manners.

Abstract: In a data transfer device, presence/absence of a prescribed header in the received request message is analyzed, and information indicating the presence/absence of the prescribed header, or information indicating either presence or absence of the prescribed header when the prescribed header is either present or absent as a result of analysis is stored. Then, when a reply message corresponding to the request message is received, the presence/absence of the prescribed header is checked by referring to the stored information, and the reply message is transferred according to a result of checking.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices. Even when the name corresponding to the data is not registered so that it is impossible to transfer the corresponding name instead of transferring the data, it is possible to reduce the amount of transfer data among the data transfer devices by transferring the compressed data in which this data is expressed in a compressed form by utilizing the name corresponding to the registered reference data.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices. Server side data transfer devices and client side data transfer devices can be provided in multiple-to-one, one-to-multiple, or multiple-to-multiple manners.

Abstract: In a client server system, the network load is reduced by using the fingerprint compression and the differential compression, by providing the proxy server at the server side and using the general purpose browser at the client side, without requiring a separate proxy server at the client side. The client downloads and installs a fingerprint cache processing engine as a plug-in.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices. Server side data transfer devices and client side data transfer devices can be provided in multiple-to-one, one-to-multiple, or multiple-to-multiple manners.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices. Even when the name corresponding to the data is not registered so that it is impossible to transfer the corresponding name instead of transferring the data, it is possible to reduce the amount of transfer data among the data transfer devices by transferring the compressed data in which this data is expressed in a compressed form by utilizing the name corresponding to the registered reference data.

Abstract: A contents distribution system uses a copyright rental use scheme in which the economical burden on the users at a time of utilizing contents can be reduced to a reasonable level, and appropriate fees can be collected for the copyrights of the contents created and provided at each stage by the raw material creators and the secondary product creators. In this system, the secondary product creator can create the secondary product contents by incorporating the raw material contents for free, and sell the secondary product contents. The end-user pays respective utilization fees to the secondary product creator and each raw material provider at a time of the purchasing the secondary product contents.

Abstract: In a client server system, the network load is reduced by using the fingerprint compression and the differential compression, by providing the proxy server at the server side and using the general purpose browser at the client side, without requiring a separate proxy server at the client side. The client downloads and installs a fingerprint cache processing engine as a plug-in.

Abstract: A contents distribution system uses a copyright rental use scheme in which the economical burden on the users at a time of utilizing contents can be reduced to a reasonable level, and appropriate fees can be collected for the copyrights of the contents created and provided at each stage by the raw material creators and the secondary product creators. In this system, the secondary product creator can create the secondary product contents by incorporating the raw material contents for free, and sell the secondary product contents. The end-user pays respective utilization fees to the secondary product creator and each raw material provider at a time of the purchasing the secondary product contents.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices.

Abstract: A contents distribution system uses a copyright rental use scheme in which the economical burden on the users at a time of utilizing contents can be reduced to a reasonable level, and appropriate fees can be collected for the copyrights of the contents created and provided at each stage by the raw material creators and the secondary product creators. In this system, the secondary product creator can create the secondary product contents by incorporating the raw material contents for free, and sell the secondary product contents. The end-user pays respective utilization fees to the secondary product creator and each raw material provider at a time of the purchasing the secondary product contents.

Abstract: At a data transfer device for transferring a request message from a first communication device to a second communication device, and transferring a response message containing a response data from the second communication device to the first communication device, an identifier to be allocated to the response data contained in the response message is generated according to a content of the response data, and a re-direct response message for re-directing the first communication unit to a URL containing the identifier is transmitted to the first communication device, instead of transmitting the response message, when the response message is received from the second communication device, and the response message containing the response data stored in the memory in correspondence to the identifier contained in the URL is transmitted when the request message for the URL containing the identifier is received from the first communication device.

Abstract: In a data transfer scheme using a caching technique and/or a compression technique which is capable of reducing the network load of a network connecting between data transfer devices, correspondences between data and their names are registered at the data transfer devices and the corresponding names are transferred, instead of transferring the data, for those data for which the correspondences are registered, so that it is possible to reduce the amount of transfer data among the data transfer devices.

Abstract: A contents distribution system uses a copyright rental use scheme in which the economical burden on the users at a time of utilizing contents can be reduced to a reasonable level, and appropriate fees can be collected for the copyrights of the contents created and provided at each stage by the raw material creators and the secondary product creators. In this system, the secondary product creator can create the secondary product contents by incorporating the raw material contents for free, and sell the secondary product contents. The end-user pays respective utilization fees to the secondary product creator and each raw material provider at a time of the purchasing the secondary product contents.

Abstract: Secure communications can be achieved between a server computer and a client computer using a key management apparatus. The key management apparatus maintains a private key for decrypting information from a server or client computer. Data encrypted with a public key is transferred to the key management apparatus for decryption.

Abstract: A first calculation unit calculates a first content hash based on a file to be written in response to a write request of the file. An encryption unit encrypts the file by using the first content hash, and generates an encrypted file. A second calculation unit calculates a second content hash based on the encrypted file. An encryption file memory correspondingly stores the encrypted file and the second content hash. A content hash pair memory correspondingly stores the first content hash and the second content hash.

Abstract: In a client server system, the network load is reduced by using the fingerprint compression and the differential compression, by providing the proxy server at the server side and using the general purpose browser at the client side. without requiring a separate proxy server at the client side. The client downloads and installs a fingerprint cache processing engine as a plug-in.

Abstract: At a data transfer device for transferring a request message from a first communication device to a second communication device, and transferring a response message containing a response data from the second communication device to the first communication device, an identifier to be allocated to the response data contained in the response message is generated according to a content of the response data, and a re-direct response message for re-directing the first communication unit to a URL containing the identifier is transmitted to the first communication device, instead of transmitting the response message, when the response message is received from the second communication device, and the response message containing the response data stored in the memory in correspondence to the identifier contained in the URL is transmitted when the request message for the URL containing the identifier is received from the first communication device.