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

btw, my primary goal was illustrative not specific. persistent ID
threats are not exactly like MAC threats, but they probably lie in a
similar space. I have no major concern with the desire to be
deterministically both unique and known, I have this concern that the
mechanisms a manufacturer can use there, tend to processes (IEEE
Registry) which construct higher state (vendor-specific blocks) which
have side effects.

On Thu, Oct 6, 2016 at 10:09 AM, Dave Thaler <dthaler@microsoft.com> wrote:
> The issue with IEEE MAC's is that it's sent to untrusted observers, not that it is a stable identifier per se.
> It just so happens that you typically don't have a choice but to send it in packets such that it can be observed
> by untrusted observers, hence the need to use randomized MACs.
>
> -----Original Message-----
> From: George Michaelson [mailto:ggm@algebras.org]
> Sent: Wednesday, October 5, 2016 5:01 PM
> To: Peter Saint-Andre - Filament <peter@filament.com>
> Cc: perpass@ietf.org; Dave Thaler <dthaler@microsoft.com>
> Subject: Re: [perpass] privacy implications of UUIDs for IoT devices
>
> As an example the IEEE MAC registry is really only to provide uniqueness, but its been demonstrated to act as a passive-capture mechanism to identify probable host architecture from on-the-wire sniffs. This then leads directly to: "If its a Dell, then I know the iDrac default password so I can attempt to see if this is a badly configured Dell which has iDrac IPMI on the host address" and like attacks.
>
> Unique identifiers are being used by the cellular provider to offer price differentiated service to people on the same basic substrate.
> Which is a poshed-up way of saying you can get a SIM which is dataplan for an iPad but if you put it in your phone you are in breach of contract over the use of that SIM. I am not personally a fan of this legalism, but it is legal, and it is an ism.
>
> I think there is a fundamental tension between baked in uniqueness, probabalistic uniqueness (think ULA) and non-unique state in Layer-2 and Layer-3
>
> -G
>
> On Thu, Oct 6, 2016 at 9:54 AM, Peter Saint-Andre - Filament <peter@filament.com> 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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