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Re: Query about nonce field in Time-stamp response.



Jean-Marc Desperrier wrote:
> 
> Prashant Dambe wrote:
> 
> > Time-Stamp Protocol Response contains Nonce field as a part of signed
> > TimeStamptoken. It will be stored as a part of timestamp token. But
> > the nonce will be checkedat the time of receiption of Time-Stamp token
> > against the client generated nonce.What will be the use of Nonce field
> > stored in the Time-stamp token when in the futurethe that token will
> > be used.Should nonce be a part of TSTInfo in time-stamp token and
> > stored as part of Time-stamp token ?
> 
> Replay detection is one thing, but there can be other uses of the nonce
> field.
> 
> If you think of it, the nonce is an arbitrary choosen user identifier
> for the token ...
> So it's not so inconvenient if it's included in the payload of the
> TimeStamptoken.

Hi,

I think it's a little auxiliary means against double timestamps.
A TSA should reject a time stamp query if the same
messageImprint *and* the same nonce found in it's database. 
It's possible to get multiple timestamps ("re-new") for the 
same document,message or whatever, 
but *never* with already issued nonce value.

with kind regards
-- 
Mors certa, hora incerta. In dubio pro mille.
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