Hi, Someone else suggested the idea of Cyberoam using a timing attack. When it comes to iBoss, they certainly are blocking OBFS4. IAT modes 1 and 2 worked, so I guessed that they were fingerprinting packet interarrival times. Also note that IAT does not work behind Cyberoam.
> On Nov 17, 2016, at 3:13 PM, Flipchan <[email protected]> wrote: > > Did u only try to connect to a bridge and proxy data throw it? > > Justin <[email protected]> skrev: (17 november 2016 12:16:49 CET) >> Hi everyone, >> I’ve been doing research to see how some of the pluggable transports >> are getting blocked with DPI. I used a Cyberoam filter under my control >> for testing, and an iBoss filter at a different location. >> OBFS4 is blocked behind both filters. Cyberoam is doing some sort of >> timing attack, but I’m not sure what. When a bridge is used by lots of >> people, then it doesn’t work. Even enabling Iat mode=1 or 2 doesn’t fix >> the issue. When I tried a bridge with not many users, it worked no >> matter what Iat mode was set at. Behind iBoss, they are fingerprinting >> Packet Interarrival times. Iat mode 1 and 2 worked no matter how much >> load the bridges had on them. >> Hopefully this information can help people understand a little more >> about how these transports are filtered. >> Thanks, >> Justin. >> -- >> tor-talk mailing list - [email protected] >> To unsubscribe or change other settings go to >> https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk > > -- > Sincerly flipchan - LayerProx dev > -- > tor-talk mailing list - [email protected] > To unsubscribe or change other settings go to > https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk -- tor-talk mailing list - [email protected] To unsubscribe or change other settings go to https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk
