| 摘要 |
PROBLEM TO BE SOLVED: To easily limit users which are able to acquire data normally. SOLUTION: In entries #1 of a key table, MAC addresses MACaddress#i of terminals, and deciphering keys KEven#i and KOdd#i assigned to the MAC addresses are registered, while being made to correspond to each other. To a MAC address MACaddress#i of each entry #i, a 'Valid bit' is added, which represents whether the entry #i is valid. In this case, the same MAC address as that arranged in the section header of a received section is retrieved from the key table and according to the Valid bit, it is decided whether the entry of the MAC address is Valid. Only when the entry is effective, are the data arranged in the payload of the section decoded and outputted. |
