Abstract: An encrypting apparatus generates an encoded data from a target file, in units of blocks with a fixed length. The encrypting apparatus creates association information for a plurality of blocks in the encoded data. The association information associates each of a plurality of top encoded codes and each of a plurality of in-file positions of the plurality of blocks. The plurality of top encoded codes are positioned at a beginning of the each of the plurality of blocks in the encoded data. The plurality of in-file positions are positions of the plurality of blocks in the target file. The encrypting apparatus encrypts the encoded data in units of the blocks.

Abstract: An encrypted content and a license are separated from each other to be distributed individually, so that the encrypted content is decrypted using the license in a user apparatus. A server encrypts licenses of a plurality of encrypted contents for package sale to generate an inactive license packaged in one file and distribute the inactive license to a user terminal utilizing an activation license for package sale. An activation license for package sale is distributed in response to a purchase request from the user terminal, a plurality of encrypted licenses contained in the inactive license are decrypted, an encrypted content contained in an object for package sale is decrypted using a license corresponding thereto so that the decrypted content is reproduced.

Abstract: An encrypted content and a license are separated from each other to be distributed individually, so that the encrypted content is decrypted using the license in a user apparatus. A server encrypts licenses of a plurality of encrypted contents for package sale to generate an inactive license packaged in one file and distribute the inactive license to a user terminal utilizing an activation license for package sale. An activation license for package sale is distributed in response to a purchase request from the user terminal, a plurality of encrypted licenses contained in the inactive license are decrypted, an encrypted content contained in an object for package sale is decrypted using a license corresponding thereto so that the decrypted content is reproduced.

Abstract: An LA (License Agent) (or a license chip having the same function as the LA) is disposed in a PC (Personal Computer), a content distribution server, and a medium attached to a PD (Private Device or Portable Device) that use a license for electronic data. A content and electronic data are encrypted corresponding to a license. The encrypted content and electronic data are distributed among them. However, the license is distributed between the LAs as safe communication means. Thus, the license can be correctly managed and transferred.

Abstract: A user terminal has a file exchanging capability provided with a transmission control unit, a reception control unit, and an entry unit. As the transmitting capability by the transmission control unit, the entry unit makes an entry in an external specific server. Unless a digital certificate can be obtained for an individual public key through the server, contents is unavailable. When contents are transmitted or enabled for transmission, the transmission control unit assumes that a signature has been placed without fail. The reception control unit checks the signature of the received contents, and controls the contents to be unavailable unless a correct signature has been placed.

Abstract: An LA (License Agent) (or a license chip having the same function as the LA) is disposed in a PC (Personal Computer), a content distribution server, and a medium attached to a PD (Private Device or Portable Device) that use a license for electronic data. A content and electronic data are encrypted corresponding to a license. The encrypted content and electronic data are distributed among them. However, the license is distributed between the LAs as safe communication means. Thus, the license can be correctly managed and transferred.

Abstract: A system in which a plurality of network nodes are connected through a network, wherein when a computation object of a first network node calls a function (facility) of a computation object of a second network node, the first network node obtains a facility identification codes (numeral) of the object and the function from a remote reference table and outputs the facility identification codes through the network as a message together with the arguments of the function to the second network node. The second network node uses the input facility identification code as a key to obtain the execution address of the facility from a local reference table and executes that facility.