Re: [saag] Liking Linkability
Henry Story <henry.story@bblfish.net> Fri, 19 October 2012 13:46 UTC
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From: Henry Story <henry.story@bblfish.net>
In-Reply-To: <CABrd9SQghpi6_rVQKxYXZDtM5HwvE7Kq7SUw5zi41ZRd3y2h9A@mail.gmail.com>
Date: Fri, 19 Oct 2012 15:46:03 +0200
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References: <CCA5E789.2083A%Josh.Howlett@ja.net> <tslzk3jsjv8.fsf@mit.edu> <201210181904.PAA07773@Sparkle.Rodents-Montreal.ORG> <FB9E461D-CA62-4806-9599-054DF24C3FD9@bblfish.net> <CAG5KPzxGz+4MywjP4knfbDr2gyvqUZc1HEBXgtaDfYT+DPg5yg@mail.gmail.com> <8AB0C205-87AE-4F76-AA67-BC328E34AF5E@bblfish.net> <CABrd9SQghpi6_rVQKxYXZDtM5HwvE7Kq7SUw5zi41ZRd3y2h9A@mail.gmail.com>
To: Ben Laurie <benl@google.com>
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Cc: "public-philoweb@w3.org" <public-philoweb@w3.org>, "public-identity@w3.org" <public-identity@w3.org>, "saag@ietf.org" <saag@ietf.org>, "public-privacy@w3.org" <public-privacy@w3.org>, Sam Hartman <hartmans-ietf@mit.edu>, "public-webid@w3.org" <public-webid@w3.org>
Subject: Re: [saag] Liking Linkability
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On 19 Oct 2012, at 15:31, Ben Laurie <benl@google.com> wrote: > On 19 October 2012 13:01, Henry Story <henry.story@bblfish.net> wrote: >> >> On 18 Oct 2012, at 21:29, Ben Laurie <ben@links.org> wrote: >> >>> On Thu, Oct 18, 2012 at 8:20 PM, Henry Story <henry.story@bblfish.net> wrote: >>>> >>>> On 18 Oct 2012, at 21:04, Mouse <mouse@Rodents-Montreal.ORG> wrote: >>>> >>>>>> [...] >>>>>> Unfortunately, I think that's too high of a price to pay for >>>>>> unlinkability. >>>>>> So I've come to the conclusion that anonymity will depend on >>>>>> protocols like TOR specifically designed for it. >>>>> >>>>> Is it my imagination, or is this stuff confusing anonymity with >>>>> pseudonymity? I feel reasonably sure I've missed some of the thread, >>>>> but what I have seem does seem to be confusing the two. >>>>> >>>>> This whole thing about linking, for example, seems to be based on >>>>> linking identities of some sort, implying that the systems in question >>>>> *have* identities, in which case they are (at best) pseudonymous, not >>>>> anonymous. >>>> >>>> With WebID ( http://webid.info/ ) you have a pseudonymous global identifier, >>>> that is tied to a document on the Web that need only reveal your public key. >>>> That WebID can then link to further information that is access controlled, >>>> so that only your friends would be able to see it. >>>> >>>> The first diagram in the spec shows this well >>>> >>>> http://webid.info/spec/#publishing-the-webid-profile-document >>>> >>>> If you put WebID behind TOR and only have .onion WebIDs - something that >>>> should be possible to do - then nobody would know WHERE the box hosting your >>>> profile is, so they would not be able to just find your home location >>>> from your ip-address. But you would still be able to link up in an access >>>> controlled manner to your friends ( who may or may not be serving their pages >>>> behind Tor ). >>>> >>>> You would then be unlinkable in the sense of >>>> http://tools.ietf.org/html/draft-iab-privacy-considerations-03 >>>> >>>> [[ >>>> Within a particular set of information, the >>>> inability of an observer or attacker to distinguish whether two >>>> items of interest are related or not (with a high enough degree of >>>> probability to be useful to the observer or attacker). >>>> ]] >>>> >>>> from any person that was not able to access the resources. But you would >>>> be linkable by your friends. I think you want both. Linkability by those >>>> authorized, unlinkability for those unauthorized. Hence linkability is not >>>> just a negative. >>> >>> I really feel like I am beating a dead horse at this point, but >>> perhaps you'll eventually admit it. Your public key links you. >> >> The question is to whom? What is the scenario you are imagining, and who is >> the attacker there? >> >>> Access >>> control on the rest of the information is irrelevant. Indeed, access >>> control on the public key is irrelevant, since you must reveal it when >>> you use the client cert. >> >> You are imagining that the server I am connecting to, and that I have >> decided to identify myself to, is the one that is attacking me? Right? >> Because otherwise I cannot understand your issue. >> >> But then I still do not understand your issue, since I deliberately >> did connect to that site in an identifiable manner with a global id. >> I could have created a locally valid ID only, had I wanted to not >> connect with a globally valid one. >> >> So your issue boils down to this: if I connect to a web site deliberately >> with a global identifier, then I am globally identified by that web site. >> Which is what I wanted. >> >> So perhaps it is up to you to answer: why should I not want that? > > I am not saying you should not want that, I am saying that ACLs on the > resources do not achieve unlinkability. Can you expand on what the dangers are? > >>> Incidentally, to observers as well as the >>> server you connect to. >> >> Not when you re-negotiation I think. > > That's true, but is not specified in WebID, right? Also, because of > the renegotiation attack, this is currently insecure in many cases. WebID on TLS does rely on TLS. Security is not a goal one can reach, it is a way of travelling. So I do expect every security protocol to have issues. These ones are being fixed, and if more people build on them, the priority of the need to fix them will grow faster. > >> And certainly not if you use Tor, right? > > Tor has no impact on the visibility of the communication at the server end. You really need to expand on what the danger is. Because again I think you are thinking of the site I am connecting to as the attacker. But I may be wrong. > >> >> >> Social Web Architect >> http://bblfish.net/ >> >> >> _______________________________________________ >> saag mailing list >> saag@ietf.org >> https://www.ietf.org/mailman/listinfo/saag >> Social Web Architect http://bblfish.net/
- [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Klaas Wierenga (kwiereng)
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Josh Howlett
- Re: [saag] Liking Linkability Sam Hartman
- Re: [saag] Liking Linkability Mouse
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Harry Halpin
- Re: [saag] Liking Linkability Melvin Carvalho
- Re: [saag] Liking Linkability David Chadwick
- Re: [saag] Liking Linkability David Chadwick
- Re: [saag] Liking Linkability David Chadwick
- Re: [saag] Liking Linkability Sam Hartman
- Re: [saag] Liking Linkability Mo McRoberts
- Re: [saag] Liking Linkability Nathan
- Re: [saag] Liking Linkability Sam Hartman
- Re: [saag] Liking Linkability Nathan
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Nathan
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Nathan
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Harry Halpin
- Re: [saag] Liking Linkability Melvin Carvalho
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Melvin Carvalho
- Re: [saag] Liking Linkability Dan Brickley
- Re: [saag] Liking Linkability David Chadwick
- Re: [saag] Liking Linkability Nathan
- Re: [saag] Liking Linkability Robin Wilton
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Ben Laurie
- Re: [saag] Liking Linkability Henry Story
- Re: [saag] Liking Linkability Robin Wilton
- Re: [saag] Liking Linkability Nathan
- Re: [saag] Liking Linkability Melvin Carvalho
- Re: [saag] Liking Linkability Melvin Carvalho