| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable a digital broadcast receiving unit 101 and an IC card 151 to scramble information between them using a common key. <P>SOLUTION: The digital broadcast receiving device 101 passes "key exchange control information" enciphered by a key management center to the IC card 151. The IC card 151 decodes the enciphered "key exchange control information" using "a key exchange control information decoding key", and generates a random number after it is ascertained that the "key exchange control information" is not tampered. The IC card 151 returns the random number to the digital broadcast receiving device 101 after the random number is enciphered by "a device key peculiar to a receiving device" (Kd1). When communications are maintained between the digital broadcast receiving device 101 and the IC card 151; data are scrambled using the random number as a common key, and communications are carried out. By this setup, it can be made hard that an interface is hacked to extract information. <P>COPYRIGHT: (C)2008,JPO&INPIT |
