[LINK] RFI: Accuracy of Geo-Location Based on IP-Address
Adrian Chadd
adrian at creative.net.au
Wed Nov 28 15:38:36 AEDT 2007
Data mining is fun. Imagine if you will:
* You have an IP address at home thats static or dynamic; it doesn't
matter;
* You use an online service which can use javascript and cookies
creatively to figure out you're you wherever you login;
(You do use your real name when registering for online services, no?)
* This "IP to person" data can be correlated against "Person to Home
address" data, which I believe is public (think Electoral roll);
* This "person to home address" data can be correlated against
"home address to proprty location" data (which again, I believe
is all public data);
* Voila.
Adrian
On Wed, Nov 28, 2007, Roger Clarke wrote:
> Following recent discussions, I've become concerned about how
> IP-Address Look-Up works, and how accurate and how precise it is.
>
> Inaccuracy and imprecision lead to misunderstandings, and perhaps
> shortly to erroneous decision-making - with inevitable harm to the
> less powerful (e.g. consumers, citizens, employees).
>
> Accuracy and precision bring with them very substantial
> privacy-invasiveness and the risk of quite frightening power for the
> State and for corporations.
>
> I did some experimentation, and have drawn some inferences. Details below.
>
> I'd greatly appreciate review, corrections, enhancements, and
> pointers to authoritative materials.
>
> ________________________________________________________________________
>
> Summary of Results
>
> My assumption had been that IP-Location services depended on IANA
> tables, the regional NICs - in our case APNIC, and reverse-DNS
> entries. (Details on relevant URLs that I'm aware of are at the
> bottom of this message).
>
> That set only gets down to IAP level. The recent fracas about
> government departments amending Wikipedia entries showed how there
> was plenty of room for debate about which organisation was actually
> using which IP-addresses.
>
> I did a test using my own IP-address (details below). Two services
> produced nonsense, but two others are a matter of serious concern.
>
> They disclosed the Latitude and Longitude of my street-address
> accurately and at a level of precision of 3 decimals of Lat/Long
> (about 100 metres).
>
> By comparison, street-address lookup appears to use that 3-decimal
> data, but also 5 decimals of Lat/Long (about 1 metre precision).
>
> One apparent way in which those IP-Location Services could work are:
>
> (1) get access to the address of the customer's registration.
> A reasonable assumption would be the records held by my ADSL-
> provider (TPG) or by the telephone-line provider (Telstra); and
>
> (2) use the G-NAF scheme at http://www.psma.com.au/g-naf
> to extract Lat and Long that corresponds to the street-address
>
> Is that likely to be the mechanism?
>
> If that's the case, how do I frame a complaint about the divulging of
> the address by TPG or Telstra? (One is an overseas corporation, and
> the other an overseas company registered in Australia).
>
> _________________________________________________________________________
>
> Experimentation with my own IP-Address and Street-Address
>
>
> My SOHO router says it has the IP-address 220.245.214.2.
>
> The Reverse-DNS / arpa entry is:
> 220-245-214-2-act.tpgi.com.au
>
> Service 1 got foxed by the TPG proxy, and doesn't seem to be sure
> where it is anyway: http://ip-lookup.net/
>
> Service 2 put me adjacent to Queanbeyan hospital (20km out):
> http://www.hostip.info/
>
> But Service 3 is chilling: http://www.ip2location.com/
> delivering -35.283 LATITUDE, 149.217 LONGITUDE
>
> And Service 4 is similar: http://www.geobytes.com/IpLocator.htm
> delivering -35.2830 and 149.2170
>
> I did more detailed testing using Service 3.
>
> http://www.ip2location.com/ gives:
>
> >IP Address: 220.245.214.2
> >Location: AUSTRALIA, AUSTRALIAN CAPITAL TERRITORY, CANBERRA
> >Latitude / Longitude: -35.283 LATITUDE, 149.217 LONGITUDE
> >Connecting through: TPG INTERNET PTY LTD
> >Time Zone: UTC +10:00
> >
> >You're using proxy server in
> >
> >Proxy IP Address:203.26.16.66
> >Location: AUSTRALIA, NEW SOUTH WALES, WEST WYALONG
> >Latitude / Longitude: -33.917 LATITUDE, 147.217 LONGITUDE
> >Connecting through: TPG INTERNET PTY LTD
> >Time Zone: UTC +10:00
> >Net Speed: DSL
>
> [The Time Zone is wrong (should be UT+11)
> [The proxy-server has me mystified, particularly in West Wyalong
> [This service also mistakes the proxy for the visitor, and (probably)
> mistakes the location of the proxy: http://freeipservices.com/
>
> Using Multimap.com.au on 78 Sidaway St, Chapman ACT 2611 delivers an
> accurate map, and the coordinates:
> -35.283%20LATITUDE,%20149.217%20LONGITUDE
>
> http://www.multimap.com.au/maps/?hloc=AU|-35.283%20LATITUDE,%20149.217%20LONGITUDE#t=l&map=-35.35577,149.03423|17|4&loc=AU:-35.35577:149.03423:17|78%20Sidaway%20St,%20Chapman%20ACT|78%20SIDAWAY%20STREET,%20CHAPMAN%202611
>
> So the Multimap lookup on street-address provides the identical
> coords to those delivered by IP-Address Look-up on that service.
>
> _________________________________________________________________________
>
> http://www.ip2location.com/aboutus.aspx
> IP2Location.com is a subsidiary of Hexasoft Development Sdn. Bhd.
> ("HDSB"), an Internet R&D company based in Penang, Malaysia.
>
> http://www.geobytes.com/Contact_Us.htm
> The site appears to provide no street-address and no phone-number.
> The ARBN is shown as 091 652 961.
> The Business Entry Point look-up at http://www.abr.business.gov.au/ gives:
> Geobytes Inc. QLD 4503
> ASIC shows it as a registered foreign business since 18/02/2000, at
> Griffin QLD 4503. Griffin is in the Pine Rivers area on the northern
> outskirts of Brisbane (adjacent to Redcliffe).
>
> _________________________________________________________________________
>
> At first, I was mystified by the following:
>
> At my latitude, 1 degree = 111,000 metres; so 1/1000th of a degree
> is still 111 metres: http://www.mysundial.ca/tsp/lat_long.html.
>
> So how does the Lat and Long measure pin down a point on my property
> boundary, and distinguish my block from the other 20 or so within a
> 111m radius?
>
> I then saw that the Multimap data carries two sets of data. The
> additional set is loc=AU:-35.35577:149.03423:17
>
> That's Lat and Long in a form 100 times more precise, i.e. to c. 1
> metre. But the two differ:
> - -35.35577 : 149.03423:17
> - -35.283 : 149.217
>
> Interestingly, MapQuest using the 3-decimal coords first gave me a
> location on a rural property just north of Canberra Airport:
> http://www.mapquest.com/maps/map.adp?searchtype=address&formtype=address&latlongtype=decimal&latitude=-35.283&longitude=149.217
>
> Then on repeating the request it gave me identical results to the
> rather different location indicated by the more precise coordinates:
> http://www.mapquest.com/maps/map.adp?searchtype=address&formtype=address&latlongtype=decimal&latitude=-35.35577&longitude=149.03423
>
> [Do these services get flushed through the NSA en route, in order to
> deliver US Administration-approved false results??
>
> Maybe not:
>
> Using this value-added service over Google
> http://www.gorissen.info/Pierre/maps/googleMapLocationv3.php
> and keying the street-address, I get the coords:
> -35.355771;149.034240
>
> And using the 3-decimal coords, I get the property north of the airport.
>
> The difference between the two is 7km N-S and 18km E-W, and that
> cross-checks with my local knowledge of about 24km driving-distance.
>
> So the more precise measure also appears to be the accurate one.
>
> _________________________________________________________________________
>
>
> My original assumption had been that IP-Location services depended on:
>
> 1. IANA tables
> http://www.iana.org/ipaddress/ip-addresses.htm
> http://www.iana.org/assignments/ipv4-address-space
>
> 2. the regional NICs - in our case APNIC:
> http://www.apnic.net/services/ipv4_guide.html
> http://www.apnic.net/db/ranges.html
> http://ftp.apnic.net/stats/apnic/delegated-apnic-latest
>
> 3. reverse-DNS entries:
> http://wq.apnic.net/apnic-bin/whois.pl
>
> See especially:
> http://www.apnic.net/db/ranges.html#geographical
> http://ftp.apnic.net/stats/apnic/README.TXT
>
> _________________________________________________________________________
>
>
> --
> Roger Clarke http://www.anu.edu.au/people/Roger.Clarke/
>
> Xamax Consultancy Pty Ltd 78 Sidaway St, Chapman ACT 2611 AUSTRALIA
> Tel: +61 2 6288 1472, and 6288 6916
> mailto:Roger.Clarke at xamax.com.au http://www.xamax.com.au/
>
> Visiting Professor in Info Science & Eng Australian National University
> Visiting Professor in the eCommerce Program University of Hong Kong
> Visiting Professor in the Cyberspace Law & Policy Centre Uni of NSW
> _______________________________________________
> Link mailing list
> Link at mailman.anu.edu.au
> http://mailman.anu.edu.au/mailman/listinfo/link
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