Transcript SkypeMorph: Protocol Obfuscation for Tor Bridges

SkypeMorph: Protocol
Obfuscation for Tor Bridges
Hooman Mohajeri Moghaddam Baiyu Li  Mohammad
Derakhshani. Ian Goldberg
Presented by Ganbi
Outline
1. Overview
2. Problem
3. Solution
4. Questions
Anonymity
Is it Important?
People’s lives depend on it
Authoritative Government vs. Activist Groups
Syria, Egypt, China
Answer: Tor
Tor Overview
Tor Overview
Tor Overview
Tor Problem
The public list of Tor relay nodes can give away all the
IP addresses.
To fix, developers added “bridge”
Tor Problem
Tor Problem
Bridge
4 Ways to get Bridge IP
https://Bridges.torproject.org will tell you few based
on your IP address and location
Mail [email protected]
Via social network
You can set up your own and tell your target users
directly
Problem
Slowly China was able to block most Bridges by
probing
DPI (deep packet inspection) is still possible
Solution/Paper
Pluggable transports
SkypeMorph
Disguise the Tor packets to look like Skype traffic by
using already existing Skype VoIP protocol and user
authentication system.
Solution
Bridge
Advantages
Anyone can use, it’s free!
Can transfer reasonable size of data = no bottleneck
Encryption already built in
In order to stop Tor, they also have to stop legitimate
Skype calls, which is highly unlikely
Another 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