发明名称 |
APPARATUS AND METHOD FOR SINGLE ENCRYPTION WITH MULTIPLE AUTHORIZATION OF DISTRIBUTED CONTENT DATA |
摘要 |
A content data distribution system uses a single key and multiple program authorization to transmit a plurality of programs in multiplexed data packets such as those used in Digital Video Broadcasting. A receiver (30) has a memory, a descrambler (20) and a processor (32). Authorization indicators are transmitted among said data packets and stored in the memory. The authorization indicators identify a plurality of authorized data packets corresponding to at least one authorized program and further identifies a plurality of unauthorized data packets corresponding to at least one unauthorized program. Only authorized data packets are output from a receiver in decrypted form. Null sets are substituted for unauthorized data packets. Data packet tables may be rebuilt as necessary to replace tables lost in null set substitution. One key is used to encrypt all programs. Alternatively, a number of keys fewer than the number of authorized programs may be used for encryption. The keys may themselves be encrypted for transmission.
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申请公布号 |
WO2004068771(B1) |
申请公布日期 |
2004.12.02 |
申请号 |
WO2004US02083 |
申请日期 |
2004.01.27 |
申请人 |
WEGENER COMMUNICATIONS INC.;LIVADITIS, ELIAS J.;KENNEDY, KEVIN |
发明人 |
LIVADITIS, ELIAS J.;KENNEDY, KEVIN |
分类号 |
H04L;H04L9/00;H04N7/16;H04N7/167;(IPC1-7):H04L9/00 |
主分类号 |
H04L |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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