CONTENTS TRANSMITTING DEVICE, CONTENTS RECEIVING DEVICE, CONTENTS TRANSMITTING PROGRAM AND CONTENTS RECEIVING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a method, a device and a program for transmitting/ receiving contents, in which efficiency is improved when descrambling scrambled contents, a cryptographic key is easily managed when descrambling the contents, and the copyright of the contents can be protected. SOLUTION: A system is composed of a contents transmitting device 3 for enciphering and transmitting contents and a contents receiving device 5 for receiving the contents, the contents transmitting device 3 is provided with a contents scramble part 7 for enciphering the contents by using a scramble key Ks, a contents key Kc, a work key Kw and a master key Km and a multiplexing part 9 for multiplexing the contents and sending them as multiplex enciphered contents and the contents receiving device 5 is provided with a demultiplexing part 13 for receiving and demultiplexing the multipled enciphered contents and a contents descrambler part 15 for obtaining the contents by deciphering enciphered information demultiplexed by the demultiplexing part 13.