Re: [openpgp] Offline key flag

[David Shaw <[e-mail]>]

On Mar 5, 2013, at 11:53 AM, Werner Koch <[e-mail]> wrote:

> On Tue,  5 Mar 2013 17:30, [e-mail] said:
> 
>> Can you give an example why would someone want to publish that their private key is offline?  I'm not sure I see a use for that.
> 
> I have two encryption keys but only one marked as offline.  If someone
> wants to send a quick message he would encrypt to the non-offline key.
> If he has to tell me something really secret, he would select the
> offline key, assuming that I will move the message to a non-networked
> box where the offline key is stored.

Ah, that's a good point.  It's still up to the sender which key to use, but you can choose to give a hint.

> I am not sure whether this is really useful for most users, but split
> and group keys are also somewhat esoteric and not even defined in
> OpenPGP.

Yes.  I've wondered about the split key bit in the past.  The group key bit seems fairly straightforward: if the bit it set, then the verifier of a signature is effectively being told the sender isn't a person, but a group, so the verifier can't expect that a single person was responsible (and similar logic for encryption).  Of course, there is nothing forcing the owners of a group key to set the bit, but if they want to, it's there.

David