发明名称 |
PROTOCOL FOR CONTROLLING ACCESS, THROUGH SPECIFIC TIME RANGES, TO SCRAMBLED DATA |
摘要 |
<p>The invention relates to a protocol for controlling access to scrambled data in specific time ranges, using access control messages ECM. The protocol consists: in assigning (A) each access control message ECM a number (T<SUB>j</SUB>) satisfying a monotonic non-decreasing function, the messages representing a timebase formed by a plurality of individual time intervals for sending successive quanta of information; in detecting (B) in each descrambling terminal the numbers of the access control messages, and then, in response to a user request (UR) from the user; in selecting (C) an access control message number that corresponds to the sending time of the request to constitute a time origin (T<SUB>jo</SUB>) of the timebase; and in authorizing (D), (E) access to the scrambled information as a function of a specific access criterion with reference to the origin (T<SUB>jo</SUB>) and over a time range corresponding to a plurality of individual time intervals defining a plurality of successive quanta of scrambled information. Application to pay TV access control.</p> |
申请公布号 |
EP1488642(A1) |
申请公布日期 |
2004.12.22 |
申请号 |
EP20030725268 |
申请日期 |
2003.03.05 |
申请人 |
VIACCESS |
发明人 |
BECKER, CLAUDIA;CODET, ANDRE;FEVRIER, PIERRE;GUIONNET, CHANTAL |
分类号 |
H04N21/6334;H04H20/00;H04H60/23;H04L9/08;H04N7/16;H04N7/167;H04N21/462;(IPC1-7):H04N7/167 |
主分类号 |
H04N21/6334 |
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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