DVB-CPCM
DVB Content Protection & Copy Management (DVB-CPCM or CPCM) is a
How it works
CPCM specifies a way of adding information to digital content, such as television programs, to describe how and if content may be used and shared among other CPCM-enabled devices.
Domains
CPCM can distinguish between devices inside and outside an "authorized domain" of devices. The authorized domain can include devices both in the home or in remote locations such as cars or vacation homes. It also specifies whether content should remain inside the home (the "local environment") or inside a physical region, such as a country (the "geographic area").
Robustness requirement
CPCM (as do all content protection mechanisms used for pay TV) contains a "robustness requirement" that demands that manufacturers design their technologies to resist end-user modification, which makes it impossible to implement a fully trusted CPCM in user-modifiable software like Linux.
Unlike most DRM systems, CPCM (in theory) supports a choice of robustness regimes rather than tying everyone to a single set of conditions. It is possible that different regimes may emerge e.g. distinct trust models for pay TV, free TV, or even public domain type content. Each of these could have appropriate levels of robustness requirement. It would even be possible to define a CPCM C&R regime that permits implementation in user-modifiable software, though this would probably not be trusted to receive content from most commercial services.
At this time no regime has been announced, so any restrictions have yet to be identified
Related technology
Broadcast Flag
CPCM is sometimes compared to the failed U.S.
It is worth noting that Europe does not have a single regulating authority like the FCC, so an exact parallel to the enforcement rules of the failed US approach is unlikely.
HDCP and DTCP-IP
Both HDCP and DTCP-IP are link protection "render and toss" technologies that generally prohibit the receiving device from recording or redistributing the content. Also, both are designed to prevent connection of devices that are not in close proximity to one another. CPCM by contrast can allow for recording and/or remote access depending on the specific rights granted with the content.
Publication
The full technical specification of DVB-CPCM is now published by the DVB Project and can be freely downloaded from this location.
The normative sections have now all been approved for publication by the DVB Steering Board, and will be published by
Nobody has yet stepped forward to provide a Compliance and Robustness regime for the standard (though several are rumoured to be in development), so it is not presently possible to fully implement a system, as there is nowhere to obtain the necessary device certificates.
See also
- CI+
External links
Current standard (Official sites)
- DVB Project and CPCM Specifications
- Electronic Frontier Foundation
- Fastcom Technology Fastcom Technology showed at the 50th DVB-CPT meeting (7–9 February 2007) the first demonstrator of the DVB-CPCM standard and is further developing it.