[liberationtech] Jacob Appelbaum's Ultrasurf Report

Jacob Appelbaum jacob at appelbaum.net
Thu Apr 26 15:01:45 PDT 2012


On 04/26/2012 02:03 PM, Douglas Lucas wrote:
> Hi all,
> 
> On Thu, Apr 26, 2012 at 12:44 AM, Jacob Appelbaum <jacob at appelbaum.net>wrote:
> 
>> Practically, I also think that mixmaster is an example of "great on
>> paper" and soon we'll see how it works out in the real world. Now that
>> the FBI is taking nodes left (in New York last week) and right (in
>> Austria this week) - we'll note that some of these anonymity properties
>> are coming up for a serious test. For example, if you don't compose Tor
>> and Mixmaster together, what happens when you're the only person to ever
>> connect to Mixmaster? I think the answer is that you're a suspect,
>> cryptographic evidence be damned.
> 
> Note (the arrested and alleged Stratfor hacker) Jeremy Hammond's complaint
> (
> http://www.wired.com/images_blogs/threatlevel/2012/03/Hammond-Jeremy-Complaint.pdf)
> says an "FBI TOR network expert analyzed the data from the Pen/Trap
> and
> was able to determine that a significant portion of the traffic from
> [Hammond and others'] CHICAGO RESIDENCE to the Internet was TOR-related
> traffic." It goes on to say "[Hammond's] Apple MAC address was the only MAC
> address at the CHICAGO RESIDENCE that was connecting to known TOR network
> IP addresses. The defendant [...] has discussed with [the informant Sabu]
> that he used the TOR network" and elsewhere defines Tor as "a system
> designed to enable users to access the Internet anonymously [...]"
> 
> Because the FBI connected the only Tor use the Pen/Trap picked up with
> Hammond's specific MAC address, and because as Jacob pointed out elsewhere
> in this thread "members of police forces around the world use Tor, as does
> the Internet Watch Foundation," the Hammond complaint does not per se
> indicate that the FBI finds Tor use in itself suspicious. (Nor am I trying
> to knock Tor; I myself use it.) But -- the FBI has a Tor network expert? I
> wonder what the expert's job duties are, how many Tor experts they have,
> and what implications there might be of the FBI having a Tor expert(s).
> Anyone know? There is also the issue of ISPs throttling or potentially
> throttling Tor traffic, which is a form of suspicion.


That's a great question for a FOIA directed at the FBI - I think we'd
all like to know!

> 
> This is a tangent, but I wonder why Hammond didn't routinely spoof his MAC
> address. I guess it wouldn't have mattered, though.
> 

I think that is irrelevant - they probably would have resorted to RF
fingerprinting or something else, such as who was in the suspect's
house, if it wasn't made easier by this trivial example. I think it's an
example of how hard it is to anonymously do anything - Tor did a
perfectly fine job from the sound of it - the thing that mattered was
the human element. Lots of bad stuff to go around in the human element
in this case and many others.

All the best,
Jacob



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