Re: [Rats] About (E)UID's

Michael Richardson <mcr+ietf@sandelman.ca> Fri, 14 February 2020 11:50 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
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Comments: In-reply-to Michael Richardson <mcr+ietf@sandelman.ca> message dated "Fri, 14 Feb 2020 07:26:48 +0000."
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Date: Fri, 14 Feb 2020 12:49:55 +0100
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Subject: Re: [Rats] About (E)UID's
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Michael Richardson <mcr+ietf@sandelman.ca> wrote:
    > Laurence Lundblade <lgl@island-resort.com> wrote:
    >> Here’s some text we might add:

    >> UEID’s are intended to be globally unique permanent device identifiers,
    >> but these characteristics rely on the implementors of device following
    >> the specification well. A relying party, particularly one dealing with
    >> a very broad variety of devices from different manufacturers, may wish
    >> to take into account other data in the token to uniquely identify the
    >> device. For example they might consider a hash some or all of the UEID
    >> + oemid + hw_version + signing_key as the unique identifier of the
    >> device. Note these are all values that are permanently set for a device
    >> at time of manufacturer.

    > Since the Relying Party needs to vest trust in the Verifier, it seems that
    > the verifier out to calculate this hash, and it should be a new claim.

    > a) it has access to this information.
    > b) there are fewer Verifiers than Manufacturers

Let me restate: a Relying Party has relationships with fewer Verifiers than
there are Manufacturers.  Maybe worst case Manufacturers:Verifiers will be
1:1, but in better cases where a Verifier providers services for many
manufacturers that ratio could be different, and thus in general, the RP will
have fewer relationships with Verifiers than Manufacturers.

    > c) the OEMID/HW_Version may well be personally identifier information which
    > should not be passed on to the Relying Party.
    > (Although I guess, if we are forming a hash over it, it becomes trackable)

    > -- 
    > ]               Never tell me the odds!                 | ipv6 mesh networks [ 
    > ]   Michael Richardson, Sandelman Software Works        | network architect  [ 
    > ]     mcr@sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [ 
	
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Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
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