发明名称 |
A system for controlling access to broadcast transmissions. |
摘要 |
A system for controlling access to broadcast transmissions including a transmitter having a transmission encoder for scrambling the broadcast, a multiplicity of subscriber receivers, each having an identical receiving decoder, containing no secret cryptographic keys, for descrambling the broadcast and a plurality of selectable and portable executing apparatus each being operatively associatable with a receiving decoder at a partially different given time and each executing generally identical operations to generate a seed for use by the associated receiving decoder to enable the receiving decoder to descramble the broadcast. |
申请公布号 |
EP0428252(A2) |
申请公布日期 |
1991.05.22 |
申请号 |
EP19900310131 |
申请日期 |
1990.09.17 |
申请人 |
NEWS DATA SECURITY PRODUCTS LTD |
发明人 |
COHEN, MICHAEL;HASHKES, JONATHAN |
分类号 |
H04K1/00;G07F7/10;H04H20/00;H04H60/15;H04H60/23 |
主分类号 |
H04K1/00 |
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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