Karsten Loesing: > On 6/4/12 7:43 PM, Sebastian G. <bastik.tor> wrote: >> Karsten Loesing: >>> On 5/16/12 8:47 AM, Karsten Loesing wrote: >>>> On 5/2/12 2:30 PM, Karsten Loesing wrote: >>>>> If nobody objects within the next, say, two weeks, I'm going to make an >>>>> old tarball from 2008 available with original nicknames. And if nobody >>>>> screams, I'll provide the remaining tarballs containing original >>>>> nicknames another two weeks later. >>>> >>>> Here we go. These are the sanitized bridge descriptors from May 2008 >>>> including original bridge nicknames: >>>> >>>> http://freehaven.net/~karsten/volatile/bridges-2008-05-nicknames.tar.bz2 >>> >>> And now, two weeks later, here are the sanitized bridge descriptors >>> containing nicknames: >>> >>> https://metrics.torproject.org/data.html#bridgedesc >>> >>> Best, >>> Karsten >> >> Here are my findings for the tarballs of March 2012. I could pick freely >> from any 2012 tarball. I picked March 2012 because it contained the >> "bridge peak" and the relays seemed stable. > > Results are that 205 of your 308 guesses (66%) were correct in the sense > that a bridge was at least once running in the same /24 as the relay > with similar nickname. At any time in March 2012, you'd have located > between 26 and 46 bridges (1.7% to 3.3%) with 37 bridges (2.5%) in the > mean via nickname similarity.
That sounds good from my point of view as an attacker. It's not too bad. > Your accuracy went up from 30% in your May 2008 analysis to 66%, but the > overall fraction of bridges you'd have located went down from 10% to > 2.5% in the mean. >From my point of view as a user it's good that the overall fraction decreased. > I think we can live with an adversary being able to locate 1 out of 40 > bridges if the operator assigns a similar nickname and runs it on a > nearby IP address. You should get more people to run bridges with names of already existing relays that are not their own. That would give a higher false-positive rate. (True, it would but I'm just kidding) More bridges overall would be wonderful. > If you think you can come up with a vastly improved rate of located > bridges of, say, 5% or more, I can look at another findings.txt of yours > for a different month than March 2012. Unless I can come up with an idea to exclude false-positives that's unlikely. Well I went up from 30% to 66%, but I don't know why that was the case. > If not, let's conclude this analysis and assume that publishing bridge > nicknames is safe enough---until somebody shows us that we're wrong. I consider that publishing bridge nicknames is safe enough for achieving the goals (counting EC2, searching them via Atlas), unless somebody (myself not excluded) shows us that we're wrong. > Again, thanks for running this analysis! Thank you for your work. I did this because, a) I had the idea to look at the data b) you told me it's useful c) I wanted to know how many can be located. Finally I can say that it was a fine experience and I learned something (at least about processing the data). > Thanks, > Karsten > Once again, thank you. Best, Sebastian _______________________________________________ tor-dev mailing list [email protected] https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev
