Subject: Re: TSA Response serialNumber Field

From: Peter Sylvester <[email-masked]>
Date: Fri, 2 Jun 2000 10:11:25 +0200 (MET DST)

> That is up to each TSA to specify, according to my suggestion.  And
> I recall that it always makes sense to talk about "mean" and "standard
> deviation" for *any* distribution of like things (apples with apples)
>  -- even if the distribution is not Normal (Gauss).

I wonder how the note of the post office etc would look like (flame waring on):

  Dear user of a time stamp :
  We are giving you this time stamp, you know, we do our best (95%) to have
  a good time, but well, it might happen that, so we just tell 95% and then
  well, if you don't need it better than 1 second, then it is 99% but still
  there is something left, so we are really sorry, but we can't tell you
  more, and obviously we do not know how a relying party may interprete this
  anyway. You know, the background of this is that unfortunately the machine
  that is reading the atomic clock and the atomic clock are made by unperfect
  material, it's similar like the 3 of 5687 nails don't have the right size. 
  Actually we look after the values from time to time, so next time, please
  remember that we highly recommend to arrive at the airport two hours before
  the plane leaves...

A relying party (for example a fiscal authority that verifies whether
you met the deadline):

  - Your declaration is due before midnight. 
  - You've got a time stamp that is shortly (n hours) after midnight ==>
      no technical decision is made, 
  - A clerk is inspecting your declaration, your previous declarations
    etc; whether you pay correctly etc., an explanation from you why
    you think you are late, etc. the clerk obviously has seen the
    info at the TV which just explained that a huge thunderstorm has
    destroyed one third of the electric network of the country just
    during that night. 
  - The cleark acts or doesn't act according the rule that each rule
    has an exception.
 
> 
> BTW, just taking a look at the new IETF "glossary" should convince us
> that we may have already gone too far in our solipsistic phantasies as we
> start to rename that which we ourselves named ;-)

Fortunately the dodo in question is marked OPTIONAL, so a TSA doesn't
have to implement it at all. 

One might consider to look back at the Subject of this thread or should 
one call it threat :-)

The question was whether the actual text of requiring a strict monotonically
increasing serial could be replaced by something else or not in order
to allow unique identification, and whether or whether not ordering
among time stamps of one TSA is defined. 

PS

---

From: Ed Gerck <[email-masked]>
Date: Fri, 02 Jun 2000 10:02:49 -0700

> among time stamps of one TSA is defined.

But the specs were broken, as it is rather obvious now, and what was
supposed to be a timestamp was actually a nothing.  I guess your examples
would be much worse if the TSA did NOT inform the reliability level
and did NOT inform the expected distribution, because in such a case
instead of saying -- "gee, we may be wrong 5% of the time", the TSA
would be saying "gee, we do not know what we are saying".

BTW, the only *minor* quibble I still have with Manger is that
I do not favor a set reliability level in the standard but we should be making
that a variable to be specified by the TSA. The main reason for this is not
only to avoid fast obsolescence but also to provide room for improvement.
I will not copy again my other arguments, but they are in the archives.

Cheers,

Ed Gerck

PS: I enjoyed your "Dear user of a time stamp " declaration and I have
a similar one for digital certificates -- and this is EXACTLY what I am
trying to avoid by calling attention to the fact that just supplying
what WAS going to be supplied was simply not enough -- as  it
is clear now after much effort, I suppose.