Re: Notary signatures

[David Shaw <dshaw@xxxxxxxxxxxxxxx>]

On Thu, Apr 25, 2002 at 04:49:46PM -0700, Jon Callas wrote:
> On 4/25/2002 3:07 PM, "David Shaw" <dshaw@xxxxxxxxxxxxxxx> wrote:
> 
> > RFC-1991 defined sigclass 0x40 as a timestamp, and went on to further
> > explain its intended use ("Type <40> is intended to be a signature of
> > a signature, as a notary seal on a signed document.")
> > 
> > When RFC-2440 came out, this extra explanation seems to have been
> > lost, as 2440 defines 0x40 only as a timestamp.  A sigclass for a
> > signature on a signature would be very useful.  Any chance to restore
> > this clarification in the next draft?
> 
> It wasn't so much that it was lost, but that it was actively removed.
> 
> Only the document and certification signatures were ever implemented before
> 2440 came out. At one time, we removed all the definitions to simplify. Then
> they gradually crept back in. 0x40 became a timestamp because there were
> people who wanted to use it.
> 
> I may be wrong on this, but would it be better to introduce a new type if
> you want to do notaries? Or do this with a notation?

As I see it, all signatures can have a timestamp, so really any of
them is usable for a timestamp signature.  I'm not sure how 0x40
differs here, as it doesn't seem clear what 0x40 is a signature on.
If it is on binary data, then we have a type for that already.  If it
is on textual data, we have a type for that as well.  We even have a
type for a standalone signature-on-nothing "token".

A notary signature does not have to be class 0x40, but since 0x40 was
intended for this in the past, and (as far as I can see) does not
serve a purpose that other signature types cannot already provide, why
not make it 0x40?

David

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