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Re: ACTION-371: text defining de-identified data

From: John Simpson <john@consumerwatchdog.org>
Date: Wed, 13 Mar 2013 12:28:35 -0700
Cc: Justin Brookman <justin@cdt.org>, "<public-tracking@w3.org>" <public-tracking@w3.org>
Message-Id: <E60E4275-7EA5-4882-87B7-87C3D1304FE6@consumerwatchdog.org>
To: "Edward W. Felten" <felten@CS.Princeton.EDU>
Would we then include non-normative examples of what is and isn't de-identified?
 
On Mar 13, 2013, at 10:21 AM, Edward W. Felten <felten@CS.Princeton.EDU> wrote:

> But we should be equally clear that "de-identify" means more than just removing the most obvious identifiers from the data.
> 
> 
> On Wed, Mar 13, 2013 at 1:07 PM, Justin Brookman <justin@cdt.org> wrote:
> Shane is right that we did choose to use "deidentified" instead of "unlinkable" at the Cambridge meeting.  So I agree we probably should not use "unlinkable" to define "deidentified" in the standard.  However, I don't see why we need to define "unlinkable" at all, as it has no operational meaning, and was rejected because it implied a technological impossibility of relinking, which is not a standard that can be reasonably achieved.
> 
> Justin Brookman
> Director, Consumer Privacy
> Center for Democracy & Technology
> tel 202.407.8812
> justin@cdt.org
> http://www.cdt.org
> @JustinBrookman
> @CenDemTech
> 
> 
> On 3/13/2013 11:35 AM, Shane Wiley wrote:
> Rob,
> 
> So we're agreed unlinkability requires more processing than de-identified - good.  I would recommend we define de-identified (nearly done) and unlinkability separately to clearly demonstrate they are different points within a continuum.  We can then focus on the discussion of retention of data in its de-identified state prior to moving to the ultimate unlinkable state.
> 
> - Shane
> 
> -----Original Message-----
> From: Rob van Eijk [mailto:rob@blaeu.com]
> Sent: Wednesday, March 13, 2013 8:28 AM
> To: Shane Wiley
> Cc: public-tracking@w3.org
> Subject: RE: ACTION-371: text defining de-identified data
> 
> Hi Shane,
> 
> I hear you and understand your position. But unlinkable and de-identified are not mutual exclusive. Unlinkable data is a subset of de-identified data, they just go through another step of scrubbing).
> Adding it to the list is not hurting your position.
> 
> The key towards the middle ground remains data retention, which has to be proportionate to the purpose.
> 
> Rob
> 
> Shane Wiley schreef op 2013-03-13 16:13:
> Rob,
> 
> I thought we had agreed to not mix the "unlinkable" term with
> "de-identified" here.  In our discussions in Boston it appeared there
> was general agreement that unlinkability in a step beyond
> de-identified.  Once a record has been rendered de-identified, it can
> later further be made unlinkable (using your definition of unlinkable
> vs. the one I proposed).  This is a significant sticking point for
> those of use attempting to find middle-ground here so hopefully we can
> document the details in non-normative text but I'd ask that we remove
> mention of unlinkable in the definition of de-identified at this time
> (or else we've not really moved forward in this discussion in my
> opinion).
> 
> - Shane
> 
> -----Original Message-----
> From: Rob van Eijk [mailto:rob@blaeu.com]
> Sent: Wednesday, March 13, 2013 5:57 AM
> To: public-tracking@w3.org
> Subject: RE: ACTION-371: text defining de-identified data
> 
> Dan, Kevin,
> 
> I would really want the unlinkability in there as well. I propose to
> add the text:  made unlinkable
> 
> Normative text: Data can be considered sufficiently de-identified to
> the extent that it has been deleted, made unlinkable, modified,
> aggregated, anonymized or otherwise manipulated in order to achieve a
> reasonable level of justified confidence that the data cannot
> reasonably be used to infer information about, or otherwise be linked
> to, a particular user, user agent, computer or device.
> 
> 
> In terms of privacy by design, de-identification through unlinkability
> is the strongest form of de-identtification IMHO.
> 
> Rob
> 
> Kevin Kiley schreef op 2013-03-12 19:03:
> Dan,
> 
> In case I wasn't being clear in my last post, I (personally) believe
> that
> 
> User-agent should *NOT* be removed from the proposed text.
> 
> I actually don't think it would do any harm to *ADD* the word
> 'Computer'
> 
> as well ( which is present in the current FTC definition ) so it
> reads like this…
> 
> Normative text:
> 
> Data can be considered sufficiently de-identified to the extent that
> it
> 
> has been deleted, modified, aggregated, anonymized or otherwise
> 
> manipulated in order to achieve a reasonable level of justified
> 
> confidence that the data cannot reasonably be used to infer
> information
> 
> about, or otherwise be linked to, a particular user, user agent,
> computer or device.
> 
> I think that covers it pretty well, and *NO* 'clarifying text' is
> necessary.
> 
> Just my 2 cents.
> 
> Kevin Kiley
> 
> Previous message(s)…
> 
> Dan,
> 
> Perhaps you can add text clarifying this perspective or, much like
> the FTC, suffice with "device" which I believe more than covers what
> you're looking for here.
> 
> - Shane
> 
> From: Dan Auerbach [mailto:dan@eff.org]
> 
> Sent: Tuesday, March 12, 2013 8:57 AM
> 
> To: public-tracking@w3.org
> 
> Subject: Re: ACTION-371: text defining de-identified data
> 
> Shane and Kevin -- The phrase "user agent" in the text is intended to
> refer to a particular user agent (not "Chrome 26" but rather "the
> browser running on Dan's laptop". I hoped that would be clear from
> context, but if it's not we can clarify. I may not be able to
> identify your device per se, but can identify that this is the same
> browser as I saw before. I think this is the case with using cookies,
> for example. It seems more accurate to me than lumping it all under
> "device", and appropriate since the text of our document is elsewhere
> focused on user agents, unlike the FTC text.
> 
> Best,
> 
> Dan
> 
> On 03/12/2013 12:19 AM, Kevin Kiley wrote:
> 
> Shane Wiley wrote...
> I had removed "user agent" in the suggested edit as this could be
> something as generic as "Chrome 26".
> It can also be something VERY specific... and tell you a LOT about
> the Computer/OS/Device being used.
> 
> In the case of Mobile... it will pretty much tell you EXACTLY what
> 'Device' is being used.
> 
> The FTC likewise does not use "user agent" in their definition.
> That's true... but BOTH definitions (W3C and FTC) currently mention
> 'Device'... and the FTC
> 
> reports go to great lengths about how important it is to exclude any
> knowledge of 'the Device'
> 
> from the de-identified data ( especially in the case of 'Mobile
> Devices' ).
> 
> Kevin Kiley
> 
> 
> 
> 
> 
> 
> -- 
> Edward W. Felten
> Professor of Computer Science and Public Affairs
> Director, Center for Information Technology Policy
> Princeton University                
> 609-258-5906           http://www.cs.princeton.edu/~felten
Received on Wednesday, 13 March 2013 19:29:30 UTC

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