Re: [MLS] confirming state recovery way forward

"Katriel Cohn-Gordon" <me@katriel.co.uk> Fri, 07 February 2020 13:52 UTC

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Date: Fri, 07 Feb 2020 13:51:59 +0000
From: "Katriel Cohn-Gordon" <me@katriel.co.uk>
To: "Sean Turner" <sean@sn3rd.com>, "Messaging Layer Security WG" <mls@ietf.org>
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Subject: Re: [MLS] confirming state recovery way forward
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I support this effort: this is one of the places where the gap between analysis and implementation is quite large, because all reliable messaging systems have a form of state recovery. While we can't necessarily fix all the issues, writing them up with a goal of at least making sure people are aware of them seems like a very good idea to me.

On Thu, 6 Feb 2020, at 4:08 PM, Sean Turner wrote:
> Hi!
> 
> tl;dr: confirming new individual draft that describes state recovery 
> (i.e., the need for ACKs/NACKs).
> 
> During the F2F Interim in January, the WG discussed how to address 
> state recovery. One reason you might want ACKs/NACKS is if you sent a 
> Commit and then some data, and the Commit is lost. In this case, your 
> data didn’t get sent and the data needs to be resent. There are obvious 
> implications because messages shouldn’t just be re-sent to the group 
> after many months. After a lengthy discussion about this and other 
> synchronization issues, the consensus at the interim was that an 
> individual draft is needed to describe state recovery-related issues. 
> After this draft is published, the WG can review it and decide whether 
> it should be accepted as a workable starting point and potential WG 
> item or be merged into an existing draft.
> 
> The chairs need to confirm the interim’s consensus on list, so please 
> let the WG know by 2359 UTC 20 February whether you disagree with the 
> way forward and why.
> 
> FYI: Jon and Emad volunteered to write this draft.
> 
> Cheers,
> Nick and Sean
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