[ebxml-cppa-comment] A "Trivial" Secure e-business Question

[Anders Rundgren <anders.rundgren@telia.com>]

A "Trivial" Secure e-business Question

Assume that you have a business message like a purchase order

    <Order>
        <From name="Big Buyer Corp.">
            <OurRef name="John Doe"/>
        </From>
        <To name="MegaCar International"/>
        <Item>10 Medium-sized SUVs</Item>
        <Comment>Make it quick please!</Comment>
    </Order>

Now assume that "Big Buyer Corp." is an advanced organization using digital signatures.

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Question:  How should the identity as expressed in a business document relate to the identity as expressed by the signer's certificate?

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Among the complications we find

1. The PKI-identity is presumably "strong" as it is vouched for by a CA, while the identity in the business document is only "claimed" by the entity itself.  ==> The PKI identity is governing?
   
2. The hierarchical naming system used by PKI (X.500) is completely different to the various naming schemes used in businesses.
   
3. Some PKI-folks claim that signatures should be tied to individuals.  Does this mean that the signer's certificate in the sample should identify John Doe of Big Buyer Corp.?
   
4. The receivers (relying parties) are automated processes supposed to securely handle similar messages from numerous business parties.
   
5. Current e-commerce standards like ebXML and Web Services does not address this basic question.

One can note that the only PKIs working on a global scale, are building on a one-to-one identity mapping between the entity's perceived identity and the identity as expressed in the certificate.  Yes, I of course refer to e-mail and web-server certificates.   Other aspiring users of PKI, like e-commerce, have not even begun to look into this issue as apparently nobody feels that it is "their business".  Who are we wainting for?  The IETF, OASIS, W3C, EU, or the UN?  Or are we maybe waiting for Microsoft and VeriSign?.

A LONG-TERM REMEDY

To create a foundation for a more robust and "frictionless" PKI-secured e-business, I strongly believe that there long-term should be a one-to-one mapping between [basic] business message identities and certificate identities.  As the business community is never going to adopt X.500 naming, as well as having their own naming problems, this will likely require changes on both sides.  A possible scheme using the currently only globally functioning naming system (DNS/URIs), is that entities are uniquely defined by two elements:

- A naming domain (name space) based on a URI like: "http://www.visa.com/cc"
- A local identifier in that domain like: 4555-5555-2244-8888

Although the example identified a credit-card, the scheme works for just about any kind of object or entity.  An advantage of using HTTP URIs is that you usually can get further information "by clicking on the link".

Regards
Anders Rundgren
Senior Internet e-commerce Architect

+46 70 - 627 74 37