Today I’m going to talk about Tor network.

What is Tor? It is a system intended to enable online anonymity and software to connect with it. The name of the software originated as an acronym for The Onion Router.

Tor was first released in 2002, but stable version of software appeared 4 months ago. The latest version of client app was out in March, this year, so we can say that it is new technology. Tor enables anonymous use of Internet because it uses technique of Onion Routing. This is the reason why there is an onion in Tor’s logo. Method of Onion Routing consists in repeated encrypting and sending through several network nodes called onion routers. These nodes are servers, very often ordinary computers hosted by volunteers. The diagram shows how Tor works. To understand things better let’s take an example of specific users. Firstly, if Alice wants to connect with Bob’s server, her computer will get a list of all nodes from directory server. Then, Tor client picks a random path to destination server. Nodes connect with each other and create encrypted path to exchange data. Last link –

between destination server and node is unencrypted. Next connections with other servers are realized on new random paths. We see that traffic in Tor network is very complex. Thanks to that users are anonymous and it is almost impossible to guess who uses particular sites.

What about implementation of software? It contains almost 500 thousand lines of source code in C, C++, Python, Java and 14 other programming languages.

Graph shows that project has developed since itsbeginning. For example, the newest version of software protects better from leak of data. Because Tor is open-source project, code is rich in commentaries and it can be intelligible for programmers unrelated to project. Vidalia is the name of graphical user interface. It allows the user to start Tor, view it, change your virtual identity and monitor network map which we can see in the screenshot. This is a map of  network. It shows a list of available nodes. Although every server has a flag, we cannot be sure, where it is.

So, do we really need Tor? In my opinion it is very useful invention.

Internet is monitored by police and intelligence agency. They search for information about committed crimes by intercepting private mails for example.

In many countries governments carry out Internet censorship. There is national firewall in China. Chinese government blocked information about Tibetan culture among other things.

Tor enables to get illegal or secret contents and protects your identity.

Then, who uses tor? Army – to mask the connections with military servers. Human rights activists anonymously report abuse from danger zones. Journalists – “Reporters without Borders” track prisoners of conscience. Unfortunately, anonymity attracts various criminals. For example hackers share harmful code, drug dealers trade in their stuff and contract killers offer their services.

The most interesting thing in Tor network are hidden services. They are accessed through Tor specific .onion pseudo top-level domain. Until recently it was impossible to access .onion website without Tor software, especially modified browser. Now, we can use our favourite browser to connect with hidden services but it is not a safe method and doesn’t guarantee anonymity. Addresses which are used in Tor network are alpha-semi-numeric codes. They are generated automatically and make searching by search-engines harder.

Hidden Wiki is an example of hidden service. There are no robots indexing sites in Tor network so search engines have low effectiveness. Hidden Wiki collects links to useful pages. Other site, Free Bibliotheca Alexandrina, collects all kinds of books and magazines. Some of them cannot be published legally. Users can download them for free. Next one, Tor mail, enables users to send messages anonymously. Mails are sent by several servers before they exit outgoing server. Tor mail doesn’t use cookies.

Mark Zuckerberg, founder of Facebook, said the age of privacy is over. Existence of Tor Project proves this statement is false. Disclosure of Internet user’s identity is not a moral problem only. Google search engine collects information to show advertisements which are the best fitted to user. It does not show good search results but prepared for some kind of user. Duck Duck Go search engine doesn’t collect any data about users and shows links in other order than Google. It works on similar rules like Tor – data is going through several servers. So, we can say that idea of anonymous Internet has application to public, visible Internet.

If you enjoyed my presentation and want to get more information about Tor you will find more information on this website.

Thank you for your attention.