INFORMATION TRANSMITTING SYSTEM, INFORMATION TRANSMITTER AND INFORMATION RECEIVER

摘要

PROBLEM TO BE SOLVED: To prevent appropriation of contents data of each other by allowing an information receiver to decipher an individual key with a previously given distributed key, to decipher a contents key with the deciphered individual key and to decipher contents data with the deciphered contents key. SOLUTION: The control part 91 of a cipher processing part 65 allows the deciphering unit 111 of a ciphering/deciphering module 96 to decipher an individual key ciphered with an inputted distributed key through the use of a distributed key supplied from a storing module 92. Further, the part 91 allows the unit 111 of the module 96 to decipher a contents key ciphered with an inputted individual key through the use of the deciphered individual key. Then, the host controller 62 of a home server 51 reads contents ciphered with the contents key from a large capacity storing part 68 and transmits a contents key ciphered with a temporary key, the signature of a using agreement condition and the contents ciphered with the contents key to equipment outside of a group.