Synchronous stream cipher
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jun 6, 2006
Issued Date -
N/A
app pub date -
May 9, 2003
filing date -
Jun 25, 1998
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
A synchronous data-stream generator, suitable for use as a synchronous stream cipher providing copy right protection for audio/video data, generates a stream of output data items in synchronisation with a clock trigger. The data-stream generator comprises at least two parallel arranged subgenerators M.sub.i, i.gtoreq.1, such as linear feedback shift registers. The output of the subgenerators M.sub.i is combined forming the output data items of the data-stream generator. A control subgenerator C is used for generating a stream of control data items. Control means (150) comprises for at least one subgenerator M.sub.i an associated number selector S.sub.i for, in dependence on the control data item of the control subgenerator C, selecting a number n.sub.i,j from a group H.sub.i of different integer numbers. At least two numbers of the group H.sub.i are larger than zero. The control means (150) causes the associated subgenerator M.sub.i to provide at the output the selected n.sub.i,j-th data item successive to a last generated data item (effectively skipping n.sub.i,j-1 data items).
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully