W3C home > Mailing lists > Public > w3c-xml-sig-ws@w3.org > April 1999

Re: Fw: XML versus ASN.1/DER blob

From: Paul Lambert <plambert@certicom.com>
Date: Wed, 21 Apr 1999 14:23:54 -0700
To: "John Boyer" <jboyer@uwi.com>
cc: "Dsig group" <w3c-xml-sig-ws@w3.org>
Message-ID: <8825675A.0070C41A.00@domino2.certicom.com>

>These people are not trying to achieve your level of security.
I am not assuming any particular level of security.  Instead, what I am
describing is taxonomy. Biometrics do not have the same functional
characterisitics as public key cryptographic techniques.

>However, for the record, most of you seem to be missing the point.  You
can
>agree or disagree or argue about the merits of this technology all you
like.
>Unfortunately the point is that you shouldn't be arguing about the
>technology at all.  We need to let the technology provide the security.

No.  We do not need to allow any technology.

We must have a clear scope of work for this committee.  We also need clear
definitions of our terminology.  Biometrics are not digital signatures.
Biometrics are a specific type of attribute that might be carried in within
signed XML document or bound to a key in a certificate.

XML is so flexible that it is easy to define opaque blobs that require
arbitrary proprietary processing.  We are an open standards group and
should strive to create a specification that promotes interoperable
solutions.  We need to be clear on what specific technologies we recommend.

Once again, I propose that "digital signatures" be defined in the scope of
our committees to mean a public key cryptographic signature.

Paul





"John Boyer" <jboyer@uwi.com> on 04/21/99 12:50:58 PM

To:   Paul Lambert/Certicom
cc:   "Dsig group" <w3c-xml-sig-ws@w3.org>
Subject:  Re: Fw: XML versus ASN.1/DER blob




Biometrics themselves do what you say, but technologies that package
biometrics package them within their own security measures however strong
or
weak they may be.

Biometrics can be associated with a public key for added security, but that
is not the only way they are packaged.  In that case, the biometrics must
still be protected.  They can't be in the clear or they can be forged.

These people are not trying to achieve your level of security.  They are
trying to achieve a level of security commensurate with what we currently
accept on paper documents.  That's it.  The biometrics and hash must be put
together and secured.  This is the only method these people have of
associating the document with the signer.

However, for the record, most of you seem to be missing the point.  You can
agree or disagree or argue about the merits of this technology all you
like.
Unfortunately the point is that you shouldn't be arguing about the
technology at all.  We need to let the technology provide the security.

John Boyer
Software Development Manager
UWI.Com -- The Internet Forms Company
jboyer@uwi.com

>Biometrics provide nothing more that a unique identifier.  It is an
>identifier that is a little more difficult to duplicate that a name or
>serial number.  Biometrics are forgeable  Biometrics are relatively easy
to
>duplicate since they are just a string of bits.  Any strength in the
>authentication must be based on the hardware component that is used to
read
>the biometric data.  Either a public key technique or a keyed hash is
>required then to authenticate the biometric input device.  Cryptographic
>techniques are also required to prevent the modification of biometric data
>in transit for remote authentication applications.
>
>Biometrics may be an interesting attribute to associate with a key.  As an
>attribute of a key they could be used as part of an authentication or
>identification process.
>
>>There seems to be general agreement that whatever we develop should be
>able
>>to accommodate multiple signature technologies.
>
>No!  I do agree that we should support a few different public key
>algorithms.  I do agree that we may want to support encryption, key
>exchanges, or keyed hashes.  A keyed hash has it's own properties and
>should not be described as a digital signature.
>
>Paul
>
>
>
>
>
>
>Alan Kotok <kotok@w3.org> on 04/21/99 11:42:20 AM
>
>To:   "John Boyer" <jboyer@uwi.com>
>cc:   "Dsig group" <w3c-xml-sig-ws@w3.org> (bcc: Paul Lambert/Certicom)
>Subject:  Re: Fw: XML versus ASN.1/DER blob
>
>
>
>
>At 01:24 PM 4/21/99 , John Boyer wrote:
>>...
>>The pen people's biometric tokens are encrypted blobs containing
biometric
>>measures of the act of signing as well as a sha-1 or md5 hash of the
>>document being signed.  The biometrics identify the signer, the act of
>>signing implies authorization (same as paper), the hash authenticates the
>>document content, and the encryption binds the two together.  The pen
>people
>>claim that this signing technology offers an electronic solution that is
>at
>>least as secure or substantially more secure than the paper signatures
>that
>>we currently accept.
>
>There seems to be general agreement that whatever we develop should be
able
>to accomodate multiple signature technologies.  There also seems to be
>agreement that it is not the work of this group to judge the strength or
>merit of any particular technology.
>
>But it does seem necessary to understand the requirements posed by known
>signature technologies on the specifications we develop.  Therefore, I
>would assume we need to understand how signing using biometrics relates to
>the process we are more familiar with: that of encrypting the hash of a
>signature block using the private key of a public keypair.
>
>Maybe I'm a bit dense, but I can't figure out the explanation provided
>above.  What "encryption" binds the identifying information unique to the
>signer and the description of what is being signed?  Could you take us
>through that operation in more detail?
>
>Thanks.
>
>Alan
>__________________________________________________________________________
_
>Alan Kotok, Associate Chairman
mailto:kotok@w3.org
>World Wide Web Consortium
http://www.w3.org
>MIT Laboratory for Computer Science,  545 Technology Square,  Room
NE43-409
>Cambridge, MA 02139, USA     Voice: +1-617-258-5728    Fax:
+1-617-258-5999
>
>
>
>
>
Received on Wednesday, 21 April 1999 17:36:34 EDT

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