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Greetings,<br>
<br>
A while ago the Tor project rolled out Obfsproxy as
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a Browser Bundle [1], for users behind firewalls filtering SSL or
detecting other characteristics of a Tor connection, to help them
access bridges.<br>
<br>
In our recent work, SkypeMorph [2], we have tried to use Skype video
communications as our target protocol for protocol obfuscation.
SkypeMorph functionality is similar to Obfsproxy, but the connection
between the bridge and the client looks like a Skype video call (the
details of how we do this is discussed in the technical report).<br>
<br>
We also have an open-source proof-of-concept impelmenation of the
SkypeMorph available at: [3]<br>
<br>
<br>
Notes:<br>
1- At the moment our code relies on SkypeKit SDK
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[4] (a paid Skype SDK which you can get for around US$ 5) for Skype
functionalities (the README file in the package explains how one can
obtain SkypeKit). However, it can be easily ported to Skype public
API [5], so users would not have to pay for it.<br>
<br>
2- SkypeMorph and pluggable transports: Although our code can
potentially be used as a pluggable transport, there is a minor
difficulty with the pluggable transport framework that needs to be
addressed before it can host our code. As mentioned above, our code
uses Skype network for basic login stuff, so it takes a little bit
more time than what Tor expect from a typical transport (like
Obfsproxy), so the Tor client gives up building circuits after a
while. We are aware of ORControllers tricks to solve the problem,
but it does not seem to be the right way to do it and it would be
awesome if the pluggable transport were able to tell Tor that it's
working on setting up the connection, and that Tor<br>
shouldn't give up on it until it says it's ready. I am sure other
transports could also benefit from this.<br>
<br>
Hooman<br>
<br>
<br>
<br>
[1]:<a moz-do-not-send="true"
href="https://blog.torproject.org/blog/obfsproxy-next-step-censorship-arms-race">https://blog.torproject.org/blog/obfsproxy-next-step-censorship-arms-race</a><br>
[2]:<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://cacr.uwaterloo.ca/techreports/2012/cacr2012-08.pdf">http://cacr.uwaterloo.ca/techreports/2012/cacr2012-08.pdf</a><br>
[3]:<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://crysp.uwaterloo.ca/software/">http://crysp.uwaterloo.ca/software/</a><br>
[4]:<a moz-do-not-send="true"
href="http://developer.skype.com/public/skypekit">http://developer.skype.com/public/skypekit</a><br>
[5]:<a moz-do-not-send="true"
href="http://developer.skype.com/public-api-reference">http://developer.skype.com/public-api-reference</a><br>
<br>
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