[Cryptography] Proposal of a fair contract signing protocol

[mok-kong shen]

Am 24.06.2016 um 14:17 schrieb Allen:
> On Fri, Jun 24, 2016 at 4:50 AM, mok-kong shen
> <mok-kong.shen at t-online.de <mailto:mok-kong.shen at t-online.de>> wrote:
>
>     (e) I like to take this opportunity to request the general readers of
>     our group to kindly take a few minutes of their free time to think of
>     reality-near hypothetical scenarios of transactions where a contract
>     C comes into being with my protocol but either Alice or Bob could
>     afterwards have the feeling that the protocol was unfair for her/him.
>     I should be extremely grateful for such informations, since they open
>     the door for me to attempt eventually feasible amendments and
>     improvements.
>
>
> If you are not willing to provide a precise and unambiguous definition
> of what constitutes a valid contract and how to test for it, then you
> are just wasting our time.

Under a valid contract I meant what Alice in step 3 produces, which
includes the text of the contract C and the pair of visual cryptography
(X, Y) signed by both Alice and Bob, with (X, Y) exactly reproducing C.
Does that sufficiently cover your "how to test for it"? Or do you mean
anything in connection with the digital signatures of Alice and Bob?
(I assume that the signatures are properly done by them.)

M. K. Shen