[tor-talk] Importance of individual useragent items

Joe Btfsplk joebtfsplk at gmx.com
Mon Jun 23 22:50:58 UTC 2014


On 6/23/2014 2:57 PM, Jeremy Rand wrote:
> On 06/23/2014 12:11 PM, Joe Btfsplk wrote:
>> I noticed there are at least 2 different references in Torbrowser for
>> useragent over ride strings.
>>
>> The Panopticlick site picks up this one: "/Mozilla/5.0 (Windows NT 6.1;
>> rv:24.0) Gecko/20100101 Firefox/24.0/," though there's another shown in
>> about:config: extensions.torbutton.useragent_override;Mozilla/5.0
>> (Windows NT 6.1; rv:17.0) Gecko/20100101 Firefox/17.0.
>>
>> Aside from the fact there are 2 strings shown in about:config, the
>> string that Panopticlick detects shows Windows 7 (32 bit - I assume).
>>
>> Several Windows usage by version sites show Win 7 64 bit as much more
>> common.  If true, why doesn't Torbrowser use that in its useragent?
>>
>> The string in Torbrowser may be one of the most common setups? Some
>> "useragent info" sites show 64 bit OSes are more common in the string.
>> In my 1st visit to Panopticlick in a long time, using Torbrowser - it
>> showed
>>
>> Browser Characteristic:  User Agent
>> bits of identifying information:  6.73
>> one in x browsers have this value:  105.86
>> value: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Firefox/24.0
>>
>> For the useragent string alone, 1 in 106 is pretty low.
>>
> To my knowledge TorBrowser doesn't try to hide the fact that it's
> TorBrowser.  As long as all TorBrowsers are the same (which I assume is
> the case), then it shouldn't affect the anonymity set unless I'm mistaken.
>
Thanks.

Other than the fact that accessing sites comes from Tor exit nodes, they 
could easily spoof the useragent the same as one of the most popular 
strings.
That may / may not be of any value, depending on how many sites check 
for Tor exits.  Creating a set of only Tor users definitely limits the 
number of users to get lost among, especially at sites w/o many Tor users.

Maybe Tor devs aren't able to blend w/ general internet users, so the 
selected Torbrowser useragent isn't that important.


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