Re: [perpass] privacy implications of UUIDs for IoT devices

Brian E Carpenter <brian.e.carpenter@gmail.com> Thu, 06 October 2016 00:34 UTC

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From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Organization: University of Auckland
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Date: Thu, 06 Oct 2016 13:34:25 +1300
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Subject: Re: [perpass] privacy implications of UUIDs for IoT devices
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I think people need to go and read draft-ietf-netconf-zerotouch
and draft-ietf-anima-bootstrapping-keyinfra. Then explain how we
could ever bootstrap a trustworthy network without some sort of
unique bitstring per device (in practice, an 802.1AR-2009 X.509
initial device identifier installed by the manfacturer).

That doesn't mean it needs to be visible in clear after bootstrap.

Regards
   Brian

On 06/10/2016 12:54, Peter Saint-Andre - Filament wrote:
> Over on the CORE WG list, we've had a little discussion about the 
> desirability (or not) of unique identifiers for devices in the Internet 
> of Things. The message below provides some context.
> 
> I'd be curious to learn more about the attack surface lurking behind 
> Stephen Farrell's comment that having long-term stable identifiers for 
> IoT devices is a privacy-unfriendly practice because people will abuse 
> such identifiers.
> 
> To be clear, the scenarios I have in mind are not specific to CoAP and 
> don't always involve IP-based networking (the technology I'm working on 
> these days enables mesh networking over long-range radio), but they do 
> involve discovery and eventual communication that is both end-to-end 
> encrypted and as close to metadata-hiding as possible.
> 
> Thanks!
> 
> Peter
> 
> -------- Forwarded Message --------
> Subject: Re: [core] Implications of IP address / port changes for CoAP & Co
> Date: Thu, 6 Oct 2016 00:11:26 +0100
> From: Stephen Farrell
> To: core@ietf.org <core@ietf.org>
> 
> 
> Hi Peter,
> 
> On 06/10/16 00:03, Peter Saint-Andre - Filament wrote:
>> On 10/5/16 4:28 PM, Stephen Farrell wrote:
>>
>>> On 05/10/16 23:22, Dave Thaler wrote:
>>>> It is important that every device have a unique UUID that is
>>>> endpoint-address-agnostic and protocol-agnostic.
>>>
>>> Considering the privacy implications I'm not at all sure I'd
>>> accept that argument. In fact I'd argue we ought encourage
>>> that devices not have globally unique long-term identifiers at
>>> all unless there is a real need for those, and unless we
>>> understand how to control their (ab)use.
>>
>> By "identifier" do we necessarily mean "network identifier"? It seems to
>> me that it is useful to have a unique long-term identifier for every
>> device, based on its public key. Whether you can obtain a network
>> connection to that device based on such information is another story.
> 
> It is undoubtedly useful to have long term stable identifiers of
> various kinds. I'd include key IDs and public keys as such.
> 
> Turns out that it's also fairly universally privacy unfriendly
> as people will abuse such identifiers for good and bad reasons.
> 
> So I think we need to get much better at analysing when such
> things are really needed and in what scope. My bet is that a lot
> of the time a locally or probabilistically unique more transient
> identifier would be just fine.
> 
> But yeah, I can't prove that. OTOH there is a hint in the term
> "IMSI catcher" isn't there?
> 
> Cheers,
> S.
> 
>>
>> Peter
>>
> 
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