Re: [openpgp] Clarify status of subkeys with certification use

[Kristian Fiskerstrand <[e-mail]>]

On 05/25/2018 11:59 AM, Neal H. Walfield wrote:
> Hi Kristian,

Hi Neal and Justus,

> 
> Justus and I have been thinking about how to realize per-device keys
> and approximate forward secrecy.  These two things are related: if we
> want devices to do their own key rotation (and I think this is
> sensible, as the alternative is to somehow regularly transfer secret
> key material to each device), then the devices need to be able to
> generate self-signatures.  Since we don't want all devices to have
> access to the primary key, each device could have its own
> certification subkey.

Wouldn't you anyways break the per-device nature if using this
certification subkey to sign a third party keyblock, and the loss of one
of the devices impacted your validity calculation across the ecosystem?

Using this in such a per-device nature also seems to require rather
special attention from the user/client, I could easily imagine ending up
with a web of cross-signatures across multiple devices here.

On 05/25/2018 11:59 AM, Neal H. Walfield wrote:
> Consequently, please do not remove certification subkeys from RFC
> 4880bis.  If anything, I would prefer that RFC 4880bis clarifies that
> certification subkeys should be supported.

if we are removing it and not just making the current state more precise :)

In any case; I'm not sure if this is a use-case I favor much personally,
but it is an interesting concept so thanks for bringing it up for
discussion.

-- 
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Kristian Fiskerstrand
Blog: https://blog.sumptuouscapital.com
Twitter: @krifisk
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