| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital broadcast system capable of specifying a broadcast receiver that is a key flow-out source, with respect to a work key Kw flowing out of the broadcast receiver. SOLUTION: In a broadcasting apparatus 300, an ECM (Entitlement Control Message) is encrypted and transmitted by the work key Kw and an encryption key Dw that is generated on the basis of transmission key deformation information A' provided from a key management apparatus. In a broadcast receiver 300, the received ECM is decrypted by a received work key Kw' and a decryption key Dw' that is generated on the basis of reception key deformation information B. Thus, transmission/reception using the same encryption key Dw' is made possible in the broadcasting apparatus 200 and the broadcast receiver 300 on the basis of the different transmission key deformation information A' and reception key deformation information B. COPYRIGHT: (C)2005,JPO&NCIPI |
