- From: János Barta <bartakok@gmail.com>
- Date: Sat, 07 Feb 2015 22:09:17 +0100
- To: Mark Watson <watsonm@netflix.com>, Emmanuel Poitier <emmanuel.poitier@enman.fr>
- CC: "public-html-media@w3.org" <public-html-media@w3.org>
- Message-ID: <54D67EFD.2050301@gmail.com>
On 2015.02.07. 18:39, Mark Watson wrote: > > > Sent from my iPhone > > On Feb 7, 2015, at 8:13 AM, Emmanuel Poitier > <emmanuel.poitier@enman.fr <mailto:emmanuel.poitier@enman.fr>> wrote: > >> Hi Janos, >> >> all you mentioned make sense to me, and I hope to others as well. I >> hope it will be considered by UAs and will be addressed accordingly >> for the best interest of users and video service providers. >> >> Le 01/02/2015 17:37, János Barta a écrit : >>> Hi Emmanuel, >>> >>> On 2015.01.31. 17:26, Emmanuel Poitier wrote: >>>> Mark, >>>> >>>> Le 30/01/2015 16:59, Mark Watson a écrit : >>>>> >>>>> >>>>> On Fri, Jan 30, 2015 at 7:53 AM, Emmanuel Poitier >>>>> <emmanuel.poitier@enman.fr <mailto:emmanuel.poitier@enman.fr>> wrote: >>>>> >>>>> Matt, >>>>> >>>>> Le 30/01/2015 16:14, Mark Watson a écrit : >>>>>> >>>>>> >>>>>> On Fri, Jan 30, 2015 at 6:58 AM, Glenn Adams >>>>>> <glenn@skynav.com <mailto:glenn@skynav.com>> wrote: >>>>>> >>>>>> >>>>>> On Fri, Jan 30, 2015 at 7:49 AM, Emmanuel Poitier >>>>>> <emmanuel.poitier@enman.fr >>>>>> <mailto:emmanuel.poitier@enman.fr>> wrote: >>>>>> >>>>>> All, >>>>>> >>>>>> I am currently looking after the information on how >>>>>> to extend the CDM to support other DRM systems, which >>>>>> is nowadays fixed and hardcoded for each browsers (IE >>>>>> with PlayReady, Chrome with Widevine, Safari with >>>>>> FairPlay). It would be nice to ensure the EME spec >>>>>> does provide information and also how browsers would >>>>>> support that in an agnostic manner to ensure a non >>>>>> fragmented market where the user does want to play a >>>>>> protected video content whatever the browser he is using. >>>>>> >>>>>> >>>>>> I doubt if anything has changed on this front, but this >>>>>> type of specification was ruled out of scope for EME. EME >>>>>> uses the term and concept "CDM" only in a notional >>>>>> manner, and does not specify any concrete interface to >>>>>> such a component. >>>>>> >>>>>> It is likely that interface and any mechanism for >>>>>> adding/extending UA supplied CDMs will remain UA >>>>>> specific, that is, until some organization steps forward >>>>>> to standardize it (assuming UA vendors are willing to do >>>>>> that... a dubitable proposition). >>>>>> >>>>>> >>>>>> Yes, such an API is not really in scope of W3C, never mind >>>>>> just EME. Just as NPAPI for <object> was created by UA >>>>>> vendors any such cross-browser CDM API would need to come >>>>>> from the UA vendors. Of course, the open source >>>>>> implementations of EME have CDM APIs in their code, but a >>>>>> major point of EME was to bring DRM under UA control, so I >>>>>> would not expect UAs ever to support download of arbitrary >>>>>> user-installable CDMs - at least it's not clear to me how >>>>>> this could be done and simultaneously meet the privacy and >>>>>> security requirements of the specification. Whilst UAs can >>>>>> technically enforce many security and privacy properties >>>>>> through sandboxing I'm not sure they will be willing to host >>>>>> CDMs about which they have no knowledge whatsoever. >>>>>> >>>>>> …Mark >>>>> >>>>> I can understand this point, though a service provider >>>>> protecting their content will evaluate DRM systems based on >>>>> the UA CDM DRM support before using EME which is at the moment >>>>> quite split across browsers. Thanks anyway for your view on >>>>> this issue. >>>>> >>>>> >>>>> What's your alternative and how does it address the security and >>>>> privacy issues ? >>>>> >>>>> …Mark >>>> >>>> I would see a separate working group who will be in charge of >>>> offering a CDM description with security analysis based on the data >>>> flow interfacing with the CDM. It may be a consortium composed of >>>> all or the most used DRM providers to design a such component, so >>>> they would have a complete knowledge and the necessary technical >>>> constraints to ensure the required level of security delivered by >>>> the CDM component within the EME feature. It does definitely >>>> require a collaborative work to assure content protection and the >>>> legitimate use of protected content in a generic manner to let >>>> users choose their preferred way to use them. > > I would have no objection to such an initiative. But someone has to > take the initiative to create and generate interest in such an > activity and I am not sure who that would be. > > However, I am not sure that it is possible to offer the security and > privacy properties required by the specification based only on the > information flow across the boundary, so long as some of that > information is in DRM-specific, undisclosed, form. > > The sandboxes being employed by some UAs certainly try to do the best > job possible there, but UAs still need to know more than that to be > sufficiently confident of the properties of the entire system. > >>>> >>> >>> >>> do we really need to have a standard CDM solution or wouldn’t it be >>> better to focus on a standard, auditable layer amongst browser >>> components and CDM modules (as it is already available in case of >>> Firefox), called CDM/DRM sandbox? >>> In case of a Sandbox solution: >>> - CDM-Sandbox can be a “bridge” with well-defined, standard >>> interfaces >>> - DRM specific CDM can be an independent/closed/proprietary module >>> - CDM will be downloaded and activated from the website of DRM >>> provider based on user consent > > I think some people would consider this a return to the bad old days > of different ActiveX controls for each site. One of the primary > motivations for EME from our point of view is that the user is no > longer asked to install something: they choose their browser and with > that they get all the capabilities they need. > Why do we need to return to the bad old days? I hope we learned from past mistakes and we would be able to prepare a better solution. Regarding the mentioned primary motivation of EME: considering the scandal around user privacy probably it would make sense to reconsider it. (Sometimes, it is better to ask consent than believe that silence gives permission. ) >>> - Decoupled Browser and DRM layers (-> Multi-DRM support) >>> - etc… >>> >>> I think the biggest issue is that there is no interest from the >>> UI/Browser side to have a cross-platform solution. There is no doubt >>> about their intention is to set their own CDM in stone (because of >>> the additional incomes, e.g. from licenses). >>> I would like to believe that it is only my misinterpretation and >>> they (Google/Microsoft/Mozilla/Opera/Apple…) are willing to make >>> sacrifices in order to have a standard, sandbox based cross-CDM >>> solution. We will see… > > You should hunk about it from the users' point of view too, or first. > How do installable site-specific CDMs benefit users ? > Yes, definitely, I totally agree with you. Option 1: browser-dependent service (except when the service provider has a multi-KeyServer/DRM env.) -> please use/download this particular browser to access your service site... Option 2: cross-browser solution with downloadable CDMs -> you can use your favorite browser, but consent is needed to download a necessary component Option2 sounds better to me. -Jani > ...Mark >>> >>> Best regards, >>> Janos BARTA >>> 1. dia >> >> Best regards, >> -- >> Emmanuel Poitier- Chief Executive Officer (CEO) >> Enman >> >> Telephone:+33 (0)2 54 67 15 38 >> Mobile:+33 (0)780 381 124 >> Email:emmanuel.poitier@enman.fr >> Web site:http://enman.fr >> >> <emmanuel_poitier.vcf>
Received on Saturday, 7 February 2015 21:09:51 UTC