Problem with faked-system-time option

[David Shaw]

On Jun 16, 2011, at 12:12 AM, Jerome Baum wrote:

>>>> The draft spec actually called it a "notary signature", but after discussion, the name was intentionally changed to "Third-Party Confirmation signature" explicitly to avoid any confusion with a real-world notary or what they do.  The word notary is just an analogy.
>>> 
>>> Yeah and that was my point. The analogy is bad because a notary
>>> doesn't just timestamp. <snip by JB>
>> 
>> Forget the word notary.  Just erase it from your head.  If you don't like the analogy, then don't use it.
> 
> Do you not agree that a bad analogy is going to cause confusion? It
> already has, and likely will continue to.

I'm not sure how much more this dead horse needs to be beaten.  Fact: the standard used to call this a "notary signature".  Fact: the people behind the standard removed all but one mentions of the word "notary" for fear of confusing people, and the one remaining mention explicitly calls it an analogy.  Evidently, it's still confusing.  I'm not sure how many different ways I need to try and get past the horrible word "notary", but it seems to be at least one more than I'm willing to.  The original proposal for 0x50 as well as every discussion on the meaning and interpretation is online, including the thread where the title "notary" was removed, and the explicit intent of the 0x50 is restated.  I'm done with this.  If you feel it's unclear, there is a ready solution to that.

> So, how do you sign
> (i.e. timestamp) data that isn't already signed by someone else?

You use a regular old 0x00 signature.  0x50 gives you capabilities that 0x00 doesn't.  That doesn't mean 0x50 takes over all purposes of an 0x00.  0x00+notation or 0x50+notation covers either set of semantics.

> 1. timestamp-only at gnupg.org. If this notation exists on the signature,
> that indicates it is a timestamp signature.
> 
> 1 a. Should we set this notation critical, non-critical, or user's
> choice? We also had the suggestion of doing two signatures, one w/
> critical and one w/out. The idea was that the user will be inclined to
> look more closely.


I don't see any particular need beyond a straightforward "timestamp-only" at most.  Clock drift and clock resolution seems like massive overkill and overcomplexity to me, but if someone else wants it, that's the nice thing about notations - anyone can define them to whatever semantics they like.

Pick critical or not depending on the semantics you want: critical means more or less "the receiving system needs to understand this notation to properly understand/handle the signature".  It causes (intentional) incompatibility with all deployed code.  If those are the desired semantics, then you have no choice, but it's a bit of a hamper (months to years) to adoption.

David