[LINK] BlueCava tracks individual devices, assigns creditworthiness

[Birch, Jim]

Rene wrote:

> My head hurts too, but imo it's the test that's arguably flaky/not
very helpful. I ran it three times and first time it said "Within our
dataset of several million visitors, only one in 640,### browsers have
the same fingerprint as yours." (can't remember the ### numbers). Second
time it said, 426,###, third time it said 213,418. 

The site grabs everything it that it can (that isn't blocked by
NoScript, etc) like OS, browser version, fonts, plugins, and matches it
to its DB.  There are about 1.2 million records in the db.  If you've
got a locked down system or very standard system you might be quite
common.   If you are unique, you get one in 1.2 million.  If there's
another matching record you get one on 640K, 1 in 3: 430K, etc.   If the
site isn't tracking users in some other way, eg a login or a cookie, it
can't tell if you are a repeat or a new user so it must treat you as a
new user.  So the numbers go down each time.  

This is either a bad design fault, or a respectful security feature, ie,
they're not keeping identifying info.

- Jim

 


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