[encrypted-media] Remove recommendation for distinct keys for distinct policies

mwatson2 has just created a new issue for 
https://github.com/w3c/encrypted-media:

== Remove recommendation for distinct keys for distinct policies  ==
Section 1 includes the following note:
"Authors should encrypt each set of stream(s) that requires 
enforcement of a meaningfully different policy with a distinct key 
(and key ID). For example, if policies may differ between two video 
resolutions, stream(s) containing one resolution should not be 
encrypted with the key used to encrypt stream(s) containing the other 
resolution. When encrypted, audio streams should not use the same key 
as any video stream. This is the only way to ensure enforcement and 
compatibility across clients."

I don't recall discussing or agreeing to this recommendation and 
propose it should be removed.

Encrypting multiple streams with the same key and having the DRM 
enforce distinct policies (e.g. by resolution) is supported by all the
 DRMs and is widely used.

See https://github.com/w3c/encrypted-media/issues/50

Received on Tuesday, 28 April 2015 00:27:16 UTC