On Mon, Jan 23, 2017 at 7:49 AM, John Levine <[email protected]> wrote:

>
> The first is that ARC says that keys SHOULD be 2K and MUST be at least
> 1K.
>

OK, I'm convinced. I'll add that info in and also update the usage doc with
additional explanation.


> This suggests a tweak to the ARC spec that we should make anyway.  The
> way you do an algorithm migration, like the one we did from rsa-sha1
> to rsa-sha256 is to put two signatures on the message for a while, one
> with the old algorithm and one with the new one.  So a validator
> ignores signatures with algorithms it doesn't understand, and if there
> are two valid signatures with the same i=N using different algorithms,
> just pick one.
>

This sounds like something that we should definitely add so that there is
clarity, but it does add a situation where cv=unknown might happen if the
previous step only signed with an algorithm that was not understood.

--Kurt
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