SkypeMorph : Protocol Obfuscation for Tor Bridges

SkypeMorph: Protocol Obfuscation for Tor

Bridges

Hooman Mohajeri Moghaddam Baiyu Li Mohammad Derakhshani. Ian Goldberg

Presented by Ganbi

Outline1.Overview2.Problem 3.Solution4.Questions

AnonymityIs it Important?

People’s lives depend on itAuthoritative Government vs. Activist GroupsSyria, Egypt, China

Answer: Tor

Tor Overview

Tor Overview

Tor Overview

Tor ProblemThe public list of Tor relay nodes can give away all the IP addresses. To fix, developers added “bridge”

Tor Problem

Tor ProblemBridge

4 Ways to get Bridge IPhttps://Bridges.torproject.org will tell you few based on your IP address and locationMail bridges@torproject.orgVia social networkYou can set up your own and tell your target users directly

ProblemSlowly China was able to block most Bridges by probingDPI (deep packet inspection) is still possible

Solution/PaperPluggable transports SkypeMorph

Disguise the Tor packets to look like Skype traffic by using already existing Skype VoIP protocol and user authentication system.

SolutionBridge

AdvantagesAnyone can use, it’s free!Can transfer reasonable size of data = no bottleneckEncryption already built inIn order to stop Tor, they also have to stop legitimate Skype calls, which is highly unlikelyAnother big advantage: Harder to block bridges even after they are found

Two Methods

Two Methods

Works Cited Moghaddam, Li, Derakhshani, and Goldberg "SkypeMorph: Protocol Obfuscation for Tor Bridges" (n.d.): n. pag. Print.https://www.torproject.org/about/overview.html.en