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RE: Putting ObjectReferences First

From: Jim Schaad (Exchange) <jimsch@EXCHANGE.MICROSOFT.com>
Date: Fri, 29 Oct 1999 12:04:22 -0700
Message-ID: <EAB5B8B61A04684198FF1D0C1B3ACD194A70EE@DINO>
To: "'Donald E. Eastlake 3rd'" <dee3@torque.pothole.com>, "W3c-Ietf-Xmldsig (E-mail)" <w3c-ietf-xmldsig@w3.org>
I would prefer seeing that a full buffer was generated -- 512-bits or
64bytes of material.  This is based on the inner workings of SHA1 (it
operates internally on 512 bits of material at a time).  This number is
based on the memories of discussions that were held during the creation of
RFC 2631 where we put padding in during the hash computation from the
Diffie-Hellman key agree to the Key-Encryption-Key result.

jim

> -----Original Message-----
> From: Donald E. Eastlake 3rd [mailto:dee3@torque.pothole.com]
> Sent: Thursday, October 28, 1999 7:57 PM
> To: W3c-Ietf-Xmldsig (E-mail)
> Subject: Re: Putting ObjectReferences First 
> 
> 
> 
> If SHA-1 is strong enough, then 160 bits (20 binary octets or 28
> octets base-64 encoded (of which the last is always "=")) are clearly
> enough.  SET always uses 20 octet nonces.
> 
> Donald
> 
> From:  "Joseph M. Reagle Jr." <reagle@w3.org>
> Resent-Date:  Thu, 28 Oct 1999 18:38:19 -0400 (EDT)
> Resent-Message-Id:  <199910282238.SAA17353@www19.w3.org>
> Message-Id:  <3.0.5.32.19991028183759.00b84100@localhost>
> X-Sender:  reagle@localhost
> Date:  Thu, 28 Oct 1999 18:37:59 -0400
> To:  "Jim Schaad (Exchange)" <jimsch@EXCHANGE.MICROSOFT.com>
> Cc:  "W3c-Ietf-Xmldsig (E-mail)" <w3c-ietf-xmldsig@w3.org>
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> >At 14:49 99/10/28 -0700, Jim Schaad (Exchange) wrote: 
> >
> >>>>>
> >
> ><excerpt>Two ways to address this are to either 1) put a 
> random nonce in
> >the front of the signature or 2) move the data that already in the
> >signature and random forward.  The problem with the nonce is that the
> >nonce value must be transmitted as part of the signature and thus
> >increases the size of all signed documents.
> >
> ></excerpt><<<<<<<<
> >
> >
> >Nicely put Jim. What is your estimation of how large the 
> nonce would have
> >to be if one were to use one?
> >
> >
> >
> >
> >
> >_________________________________________________________
> >
> >Joseph Reagle Jr.   
> >
> >Policy Analyst           mailto:reagle@w3.org
> >
> >XML-Signature Co-Chair   http://w3.org/People/Reagle/
> >
> 
Received on Friday, 29 October 1999 15:04:26 GMT

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