This presentation provides an overview of Tor (The Onion Router) in 18 slides. It begins with defining Tor as free software that helps defend against traffic analysis to protect user privacy on public networks. It then covers the history and development of Tor, why anonymity is needed on the internet, how Tor works using onion routing and encryption, who commonly uses Tor including activists, media and law enforcement, weaknesses of using Tor, and the future of continuing to improve Tor's security and usability. The presentation concludes that Tor provides a means for safe and secure anonymous web use at no cost, though it can also be used for malicious purposes.

1. A presentation by
Alok Kumar Padhi
CSB(2), 09
1401209130
cs1452491

2. CONTENTS
2
1. What is Tor
2. History
3. Why we need Tor
4. How Tor works
5. Who uses Tor
6. Weaknesses
7. Future of Tor
8. Conclusion

3. WHAT IS TOR ?
 Tor(The Onion Router) is a
free software and an open
network that helps you
defend against traffic
analysis.
 Traffic analysis can be
used to infer who is talking
to whom over a public
network.
3

4. CONTINUED ...
 Onion Routing is implemented by encryption
in the application layer of a communication
protocol stack, nested like the layers of an
onion.
4

5. HISTORY
 The Core principle of Tor was developed in
1990s by US Navy, Paul Syverson and
Michael G.Reed and David Goldschlag.
 The alpha version of Tor was developed
by Syverson, Dingledine and Nick
Mathewson called Tor Project in 20
september 2002.
 In 2004 EFF (Electronic Frontier
Foundation) began funding Tor. In
December 2006 Dingledine, Mathewson
and five others founded “TOR”.5

6. WHY WE NEED TOR ?
 To protect us against a form of internet
surveillance known as traffic analysis.
 Tor enables user to surf the internet, send
mail, chat, instant messages, www
browsing and IRC anonymously .
 Protection from Privacy By Policy
 Tor protects two specific points of
information: website data payloads and
header information
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7. HOW TOR WORKS ?
7

8. 8

9. 9

10. VISUAL DESCRIPTION OF THE TRAFFIC
BETWEEN TOR RELAY NODES USING
ETHERAPE10

11. WHO USES TOR ?
 Family & Friends
 Activists
11

12. WHO USES TOR ?
 Media
 Military & Law Enforcement
12

13. A CARTOGRAM SHOWING TOR
USAGE
13

14. WEAKNESSES
Exit Node Eavesdropping
Bad Apple Attack
Traffic Fingerprinting
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15. FUTURE OF TOR
 To keep the network up and running in a
way that handles as many users as
possible.
 Security and usability don't have to be at
odds: As Tor's usability increases, increase
the possible sources and destinations of
each communication, thus increasing
security for everyone.
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16. CONCLUSION
 Tor has proved to be a great medium for
safe, secure and anonymous web presence
that can be provided to a user at no cost.
 Although it is available for a positive
intention, but is also used by malignant
people in fulfilling their needs.
 The Tor project has led to an optimistic
approach towards censorship and
surveillance-free internet.
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17. REFERENCES
[1] "Tor Research Home" torproject.org.
[2] "Tor: Overview" The Tor Project.
[3]"Surveillance Self-Defense: Tor". Electronic Frontier
Foundation.
[4] Dredge, Stuart (5 November 2013). “What is Tor? A
beginner's guide to the privacy tool". The Guardian.
[5] "Tor Browser" The Tor Project.
[6] Dingledine, Roger (23 January 2017). "Tor 0.2.9.9 is
released". arma's blog. Tor Project
[7] Mathewson, Nick (19 December 2016). "Tor 0.2.8.12 is
released". nickm's blog. Tor Project
[8] fossbytes.com/everything-tor-tor-tor-works/
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