Comcast joins Coral DRM crew

Let a thousand DRMs bloom

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Coral’s Nemo stands for Networked Environment for Media Orchestration and it is a combination of software agents and online connections which verify transactions.

In Nemo there are four defined sets of roles; client, authorizer, gateway and orchestrator, all communications happens over a pure IP network. Work is allocated to each level such as authorization, peer discovery, notification, services discovery, provisioning, licensing and membership creation.

The client sits in the DRM and uses the services of the other three peers, with the authorizer deciding if the requesting customer should have access to the content; the gateway takes on the role of a helper that will provide more processing power to negotiate a bridge to another architecture and the orchestrator is a special form of gateway that handles non-trivial co-ordination such as committing a new delivery transaction.

So what actually happens when a Nemo-compliant DRM wants to transfer content to another Nemo-compliant DRM? Does the file get decrypted and then re-encrypted?

“It depends on how our members decide to build their systems. One way is for the new DRM to go and get a new copy of the file from a remote source. Other systems will be set up to convert on the fly from one system to another.

“Say you take an apartment building – all served by a wireless network. The content might be available in a format my DRM can eat, and copying will happen in the most efficient way that the network can organize it.

“One DRM says ‘I don’t know or trust this other DRM’. Now it issues a request to Coral, saying ‘can you help me out?’.

“I trust you, Coral, it says, and Coral looks around and checks its policies. Maybe it authorizes a translation, maybe it transfers another new copy of the content, but whatever happens, the copy just turns up. “Under those circumstances we believe that content owners and network owners will gradually alter their policies and make them easier to work with,” said Shamoon.

The content owner has to already trust both DRMs and that’s a separate choice that the content owner makes. All that a DRM owner then has to do is to agree to trust communication to the Coral NEMO architecture and it can work with any other DRM.

What about the mobile telephony DRM that has emerged out of the Open Mobile alliance?

“We have played with OMA in the labs and we are looking at it. It was purpose built for mobiles, and its DRM has two pieces really a license server and a content server. What happens at the moment when I buy all my content from Orange and then I want to change to using O2? Can I take it with me or will my license server no longer allow me a license to view content I have already bought?

“We could be in a situation where two OMAs have separate trust chains and they won’t talk to each other.”

So how will Nemo come to market? Will it involve operating like the Digital Living Networks Alliance (DLNA) and putting together usage case scenarios and conducting plugfests where different NEMO-compliant DRMs come together and Coral members try to work out how they can work together?

“Well there’s some of that, but we hope there’s a lot more to it than that. We currently offer a compliance framework and members can test for compliance. The next thing is to define our certification process, that’s not been done yet.

“We have to work out how we will hand over trust credentials between NEMO and DRMs and we have to establish how key renewability will work. All that should be available by the end of the summer, and go through final refinements over the autumn. We think some of our members will implement during Q4 and we will be certifying DRMs by the end of the year.”

“In fact the DLNA are getting involved with Coral and its chairman Scott Smyers has got involved with Coral,” said Shamoon.

Which is pretty important, really. The DLNA says that it will only endorse other, existing standards, and not produce any standards of its own. But currently it has no recommendations to its 100 plus members on the subject of DRM. They have said that they will never endorse a standard that only works on a single architecture, which is one reason that Microsoft has made its Janus DRM independent of the Windows architecture and why it has licensed Intervideo to move Windows Media Player to run on Linux (not that it has ever gone and ahead and built it).

If Coral is put forward as a standard and receives the DLNA’s endorsement, then DLNA would be saved from having to endorse any single DRM.

So will the content partners at Coral insist that all the DRMs that they deal with use Coral?

“Obviously that’s our eventual goal that content owners will push for Coral, but they have already approved various DRMs for delivery, such as Microsoft Media DRM.

“They may choose to continue working with two or more separate worlds. For instance Windows DRM, Apple’s Fairplay and any Coral-compliant DRM. These three may never speak to each other and perhaps the Coral logo goes on all the other products and they occupy their own shelf at Best Buy and other stores.”

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