High security pay television system
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Feb 21, 1989
Grant Date -
N/A
app pub date -
Apr 22, 1987
filing date -
Apr 22, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A high security pay television system is provided in which television receivers include a decoder and with periodically changed removable memory modules. The decoder only functions to properly descramble the scrambled broadcase signal when a changeable system-wide code is available in the decoder. The code can either be carried in the memory module, or an internal code unique to the decoder and resident in the decoder can be combined with an external code in the removable memory module, and also unique to that decoder, to generate the common systemwide system code. Program viewership is written on the removable memory module which is returned to a central facility for later subscriber billing.
First Claim
Family
International Classification(s)
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- [Patents Count]
Cited Art Landscape
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