Re: [Perc] Barry Leiba's No Objection on draft-ietf-perc-private-media-framework-10: (with COMMENT)

["Paul E. Jones" <[e-mail]>]

Barry,

Thanks for the comments.  I accepted all of the suggestions and answered 
the one question below (while also making changes to the text to make 
this clear ... or attempt to do so).


>— Section 4.1 —
>It’s not clear from the diagram or explanation, so please clarify for me: there
>one e2e key per endpoint, and every endpoint knows the key for all the other
>endpoints, yes? I think it would be worth saying this clearly and explicitly,
>either here (my preference, to set it up early) or in Section 4.5.

There is one or more unique E2E keys per Endpoint, generally one per 
media flow (though the same E2E key could be used for all flows given 
the SSRCs are different for each). For each flow, these keys are 
conveyed by the sender in the full EKT Field as per the EKT Diet 
document.

I've added some text and hopefully that will appear in the next 
revision. I also felt like we needed to augment 4.5 with stating (just 
for completeness) that normal DTLS-SRTP is used to obtain HBH keys 
between Media Distributors. So I added that, too.

Paul