Re: reliable messaging - hop by hop

[Dan Weinreb <dlw@exceloncorp.com>]

   Date: Wed, 29 Aug 2001 09:54:15 -0400
   From: christopher ferris <chris.ferris@east.sun.com>

   A NRR *may* not be meaningful in a legal sense unless it is
   signed by an authorized signer. The private key for the certificate
   that is authorized *may* not be available to the MSH for security
   reasons.

   This is why it is my strong belief that NRR is an "application"
   function.

I agree with you, but I think there is an additional argument that NRR
must be an "application" function, independent of the question of the
handling of the private keys.

If an NRR is not application-level, then presumably the NRR merely
means that the message reached the MSH of the To Party, i.e. that the
message was delivered into a persistent queue at the To Party, or
something like that.

If that's all that the NRR means, it seems to me that it's not
terribly useful.  Suppose party F sends a message to party T, and gets
back such an NRR.  Later there is a dispute, and F wants to "prove"
(introduce evidence that) T really did "receive" the message, and so
it introduces the signed NRR as evidence.  T replies that, well, yes,
the message did get into its MSH, but T never actually processed the
incoming message; it was just sitting there on the disk somewhere and
nobody ever actually looked at it.  In this way T can effectively
repudiate the message in spite of the existence of a signed NRR.
So the signed NRR really doesn't help F; he might as well not have
it at all.