Subject: Re: [ietf-privacy] On Privacy for Mobility and Multihoming

From: "Hanka, Oliver" <[email-masked]>
Date: Tue, 14 Dec 2010 13:57:30 +0000

Dear Wassim,

thank you for the links. I have a comment regarding the draft-haddad-alien-threat-model-04.txt draft:

In Section 4.1. you (and the other authors) describe the possibility for a single attacker to eavesdrop for MAC addresses within the same DS. Furthermore you write that multiple attackers are required to trace a node beyond the DS boundaries which increases the 'costs' or efforts for the attacker. This of corse is correct.

In my opinion, however, the thread model misses to stress an important point. Increased tracking costs/efforts sounds like a positive aspect benefitting the target. One would consequently conclude: The higher the costs, the more unlikely an attack is. Therefore, the DS should be kept as small as possible.

This, however, contradicts the current development. As you write, several cities already operate a city-wide WLAN with a single or only a few DSs. Furthermore, in my opinion, the local (city wide) information gained due to a lack of privacy is the most interesting one. Usually in terms of privacy an attacker is not so much interested in whether the target spends his holidays in the Bahamas or Australia. Much more interesting are his local habits. Where is he working, where does he shop and what are his leisure activities? This is the advertisement relevant information for example - as well as for other attack scenarios. A target spends most of its time within its home city and therefore within a single DS (unless the target is some kind of a jet setter of course). This means that an attacker rarely needs to raise the additional efforts for a distributed attack.
In my opinion, this point should be mentioned in the thread model.

What do you think?

Regards,
Oliver

Am 11.11.2010 um 08:37 schrieb Haddad, Wassim:

> Dear all,
> 
> I would like to thank Scott for his presentation today and follow up with a request for your comments 
> on the work we have done in this area (few years ago) with a particular focus on privacy for mobility 
> and multihoming:
> 
> -  http://www.ietf.org/id/draft-haddad-alien-problem-statement-04.txt
> -  http://www.ietf.org/id/draft-haddad-alien-threat-model-04.txt
> -  http://www.ietf.org/id/draft-haddad-alien-privacy-terminology-06.txt
> 
> Comments are welcome!
> 
> 
> Regards,
> 
> Wassim H.
> 
> 

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Dipl.-Ing. Oliver Hanka
Institute of Communication Networks     Tel.: +49 89 289 23506
Technische Universitaet Muenchen        Fax : +49 89 289 23523
Arcisstr. 21, D-80290 Munich            mailto: [email-masked]
Building 9, 1st floor, Room 1936
http://www.lkn.ei.tum.de/~hanka
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