Re: protocol for proofing sending a document

From: Skybuck Flying (nospam_at_hotmail.com)
Date: 06/28/05 

Date: Tue, 28 Jun 2005 09:23:37 +0200

"Anna Kahn" <akahn@gmail.com> wrote in message
news:d9q0pk$4a8$05$1@news.t-online.com...
> Hello sci.crypt,
>
> I have the following problem, and I don't know if a solution for this is
> even possible:
>
> Assume we have 2 parties Alice and Bob. Alice wants to send a document
> to Bob. If Alice really sends the document to Bob, then she can prove to
> a third, not involved party, Carol, that indeed she sends the document
> to Bob (so Bob received the document) and there is no way for a
> dishonest Bob to claim that he never received the document from Alice.
> Further, if Alice doesn't send the document to Bob, then there is no way
> for Alice to prove to Carol, that she sends the document.
>
> Is such possible? If yes, how?

I think so... in a closed system... as long as alice, bob and carol don't
*** around with the system :)

>
> Thanks in advance,
> Anna