Re: [EME] Users of "persistent-release-message" (secure proof of key release for non-persistent licenses)?

On Wed, Mar 18, 2015 at 2:19 PM, Bob Lund <B.Lund@cablelabs.com> wrote:

>
>
>   From: David Dorwin <ddorwin@google.com>
> Date: Wednesday, March 18, 2015 at 2:30 PM
> To: "<public-html-media@w3. org>" <public-html-media@w3.org>
> Subject: [EME] Users of "persistent-release-message" (secure proof of key
> release for non-persistent licenses)?
> Resent-From: "<public-html-media@w3. org>" <public-html-media@w3.org>
> Resent-Date: Wednesday, March 18, 2015 at 2:31 PM
>
>    Several of the open bugs that have been proposed for discussion at the
> f2f relate to "persistent-release-message
> <https://w3c.github.io/encrypted-media/#idl-def-MediaKeySessionType.persistent-release-message>"
> sessions. Other than Mark, is anyone planning to use such sessions in an
> application? If so, please reply with information about your use case
> before the telecon on March 31, to give the group time to plan for possible
> face-to-face discussion.
>
>
>  It would appear that the Limited Concurrent Streams via Key Release
> <https://www.w3.org/wiki/HTML/Media_Task_Force/EME_Use_Cases#Limited_Concurrent_Streams_via_Key_Release> requires
> the "persistent-release-message" session type. Support for this use case is
> important to a number of large service providers.
>

Limiting concurrent streams is important to many content providers, but do
these large service providers to which you refer use a (persistent) secure
proof of key release to do enforce such limitations? For context, there are
other ways to enforce concurrency limits, including Limited Concurrent
Streams via Key Renewal
<https://www.w3.org/wiki/HTML/Media_Task_Force/EME_Use_Cases#Limited_Concurrent_Streams_via_Key_Renewal>
.

>
>
>  Note: This session type specifically relates to persisting a secure
> proof of key/license release for *non-persistent* licenses for later
> retrieval. It does *not* apply to release messages related to persistent
> licenses (“persistent-license
> <https://w3c.github.io/encrypted-media/#idl-def-MediaKeySessionType.persistent-license>”
> sessions) or even release messages from “temporary” sessions that do not
> need to be persisted.
>
>  David
>
>