Posts Tagged latitude
Google WiFi data collection
Google have caused quite a FUSS after their accidental collection of unencrypted WiFi data.
“Communications Minister Stephen Conroy has lashed out at Google, accusing the internet giant of the single biggest breach of privacy in history.”
Here’s the official Google response.
I posted an article in February last year on how/why the street view cars collect WiFi data and I think it’s quite a clever idea. Basically, Google holds a database of WiFi MAC addresses collected by the street view car and users of their Latitude application. This database is then used to provide location information to users without a GPS device (i.e. on your laptop).
Google aren’t denying they collect WiFi access point information. Their mistake was storing un-encrypted WiFi data. Every WiFi access point broadcasts information about itself including a unique identifier (the MAC address) which is what google want. WiFi also broadcasts all data which is transferred – such as internet banking passwords and emails – meaning anyone within a reasonable distance can collect this private information. To prevent this most WiFi links use encryption to scramble the data making it unintelligible to anyone who doesn’t know a secret password. It wouldn’t matter if Google collected encrypted WiFi data because they can’t decrypt it.
So really, if you use an unencrypted WiFi link you really only have yourself to blame. An analogy of unencrypted WiFi communications would be sitting in your house with the windows open yelling your internet banking details over a megaphone for all your neighbors to hear. An encrypted WiFi link is slightly better because you’d be yelling the details in your own made-up language. I think Google are the least of your concerns.
It will be interesting to see what comes of the various government investigations into Google’s privacy breech. Maybe here in Australia Steven Conroy could add google.com to the proposed internet filter.
Google Latitude + GoogleCar
Everyone has heard about Latitude by now. “See your friends’ locations and status messages and share yours with them.”
Ok, there’s a mountain of privacy issues surrounding it… Simple solution — turn it off. I have no intention to broadcast my location 24 hours a day. That’s just asking for trouble. But it could be very handy when you actually want your location to be known.
Anyway – what I’m interested in is how it finds your location?
Most smart phones have some sort of Location API – Here’s an example using the Symbian Location Acquisition API. Java and iPhone have similar API calls.
The other side of the API presumably uses whatever it can to get a location. GPS (possibly with the help of an A-GPS server) or some form of mobile network based “triangulation” seem to be popular.
But what if your phone doesn’t have a GPS receiver? Or you’re using the Latitude iGoogle app on your laptop? Or a desktop?
This is where things get interesting. The Latitude iGoogle app gets your location through the Google Gears GeolocationAPI which according to google, uses “your computer’s WiFi location”. What the hell is your “WiFi location”?
Well, if you can build up a big enough database of WiFi access point MAC addresses and associate each with a location, you can perform a “reverse” query to associate an AP to a location! viola! Each AP should have a 100m (or so) transmission radius, so if there are multiple APs you can “overlay” these transmission circles to get an even more accurate position.
But this theory only works if you have a lot of entries in your database and it’s regularly updated (as people add/remove/move their personal APs). How do you do this? My ideas:
- The Google street view car scans for WiFi signals as it drives around
- Every Laitude program updates the Google database while it is being used
The Street view car visits every street which gives Google a good starting point for the database. As soon as possible after this they get users to “give Latitude a try” which corrects the database with any changes since the Google car went past, making it more accurate as more users come on. To back up this Google car collection claim, I’m going to use a quote from the official google blog “Today, Latitude is available in 27 countries, and we hope to add more soon.”. How many countries do you think Google has Street View imagery for or is currently capturing? About 27 perhaps?
It’s all very clever if you ask me.
Just don’t tell anyone what Virtual Observer is currently doing with rubbish trucks…… 😉
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