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Local ECM simulcrypt. Disclosure Number: IPCOM000006993D
Publication Date: 2002-Feb-14
Document File: 1 page(s) / 67K

Publishing Venue

The Prior Art Database



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Local ECM simulcrypt

Content received in a home network needs to be protected according to DRM rules.

One could use the proprietary CA system which was used for distribution of the content to the

home network. A more useful alternative is to provide a local "baseline" CA system, which is

less complex and full-featured and typically only provides protection against unauthorized

copying. ECMs in the content then need to be converted to the rules of the baseline system,

but now information in the original ECM that cannot be represented in the baseline ECM is


To overcome this problem, a copy of the original proprietary ECM is also provided

with the content after the conversion. It could be inserted in the stream, or provided

separately. The original ECM could also be maintained as-is in the stream. A receiving

apparatus that supports the proprietary CA rules can make use of this information, and other

devices can use the baseline ECM. The proprietary ECM could for instance be used in

advanced business models like pay-per-view that are not supported by the baseline system.

In an embodiment the "Simulcrypteur" equipment as known from US-B1-6,307,939 is

used to add a baseline ECM to the content stream. In the terminology of this patent, the SYSB

ECM comprises the baseline CA information, and the SYSA ECM the proprietary, fullfeatured

CA information. The Simulcrypteur, installed in the gateway, converts (a copy of)

the S YSA ECM to the local rules and thereby produces the SYSB...