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

Brian E Carpenter <> Thu, 06 October 2016 00:34 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 1E3E71294F1 for <>; Wed, 5 Oct 2016 17:34:25 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Status: No, score=-2.7 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id EaPLsreK9tMf for <>; Wed, 5 Oct 2016 17:34:23 -0700 (PDT)
Received: from ( [IPv6:2607:f8b0:400e:c03::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 364BC1293FE for <>; Wed, 5 Oct 2016 17:34:23 -0700 (PDT)
Received: by with SMTP id r9so194977paz.1 for <>; Wed, 05 Oct 2016 17:34:23 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=subject:to:references:from:organization:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=wMCwRmZZwslDv0Z+TYfnhAmnLY1yhpXYB8UWDwTtVXI=; b=l3uchxK92f9ZOKZV0a7v38l3s58ZAzhu+00AyBfoO60/1ojSlK25iDWXpkUmO/q4zL MTeNFiv+4ns+kJ4REZzEjntSz7OOHQORXasykj4A0pXoqo8WrKXLQLUUbf9wzG5TcxJW qGWnW5aF6xcUVmt8PQOtQPTuUxk13p15x2KKJDrw8TfCYkOdXODJ0RtSy0n+jdjAOvSu UZEhW8owptrGnLug4Jw0wowc5miz9YGk0tChWQfHiE9a7sN1c9HHcdixpUsxn00b5AZY gls2sDRh3WEEtmFAyYPuZzT3Vcl6tofnDU06SMB4QBktDpD972ZpjMwowxTAkAGuZbFR kalA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20130820; h=x-gm-message-state:subject:to:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding; bh=wMCwRmZZwslDv0Z+TYfnhAmnLY1yhpXYB8UWDwTtVXI=; b=lsFIA4N2xsLAF2UBfl0e+3lcVzF2ZANz1w5NSHVvSZ10ImQE4eZg/LnYxKTxFz5DcE tLCavZud3u4Ee23AOKi3hq1aWLzkd/DPna6B9cxIZyjCcp0fD5i6Lh4OpGF/y+mBRMmJ Yf+6UEOptisQQK+lA/JGFwgtto68LxrvA3rzM+JiDlOM3TjI1Oa72m7VI5+yZtmLlVQF BDkFZGs5bpZweE7UDmxxqCWcODqt4pU3L9YSzOxLOaEWFHb2hgEbnu8/eZ6YDYR7wBde 9iF519F0owtdHFe/atP2VbUtwIcaMmOV21JcJCnZUFqZwXpbFKUoR3v2MbS4ABoHYkXb 4Thw==
X-Gm-Message-State: AA6/9RllAlfK1UQDO1ber91+A3FmmuWyxakW1mF7+nzZd7YuLUoROqbaOo01s37ud65ybA==
X-Received: by with SMTP id o7mr2035839pao.19.1475714062360; Wed, 05 Oct 2016 17:34:22 -0700 (PDT)
Received: from ?IPv6:2406:e007:4ce3:1:28cc:dc4c:9703:6781? ([2406:e007:4ce3:1:28cc:dc4c:9703:6781]) by with ESMTPSA id tn5sm17170966pac.6.2016. for <> (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Oct 2016 17:34:21 -0700 (PDT)
References: <> <>
From: Brian E Carpenter <>
Organization: University of Auckland
Message-ID: <>
Date: Thu, 6 Oct 2016 13:34:25 +1300
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0
MIME-Version: 1.0
In-Reply-To: <>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Archived-At: <>
Subject: Re: [perpass] privacy implications of UUIDs for IoT devices
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: "The perpass list is for IETF discussion of pervasive monitoring. " <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Thu, 06 Oct 2016 00:34:25 -0000

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.


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: <>
> 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
> _______________________________________________
> perpass mailing list
> .