What is Tor and how do I use it?

What is TOR
What is TOR

TOR is a protocol that allows you to surf the web anonymously. Tor transmits information through a multitude of computers before accessing the requested computer. This system was designed to fill the gaps of proxy servers.

Data packets pass from one router to another, leaving few traces on their origin. Even if it is theoretically possible to find a user, it is very difficult to do this, because each router has little information on its successor and its predecessor (only the exit node is known).

Today, Tor's enemies are focusing their force on these exit nodes, trying to identify them.

The use of Tor networks is common for surf anonymously, to access a site reserved for certain IP addresses or to access the famous " darknet ».

How does the TOR protocol work?

Here is an HTTP Request without Tor

By entering an address like www.funinformatique.com, your computer will connect to the www server.funinformatique.com and ask for the index.php page.

And here is an HTTP request with Tor

With the use of the Tor network, when you type www.funinformatique.com, instead of connecting to the server directly, your PC (A) will go through a PC (B) which will request information from a PC (C) and so on. The final PC, say a PC (D) will request the page from the server (for example FunInformatique.com) and retransmit it to the PC (C) and so on to return to your PC (A) which will receive the requested page.

Warning: Tor prevents you from knowing where you are, but does not encrypt your communications.
Instead of taking a direct path from sender to receiver, communications that pass through the Tor network take a random path through the various Tor computers, confusing the tracks.
The communications are encrypted between the various nodes (computers) on the other hand the data remains transmitted in the clear between the last node and the server of the site. Any egress node has the ability to capture the traffic passing through it.

If you send an email and sign with your first and last name, you will obviously not be anonymous!
Encrypt data initially, even before going through the network, perhaps a solution to increase confidentiality.

How do I use the Tor browser?

Go to the site Torproject.org, click on Download Tor then click on Download Tor Browser. This is the easiest technique to use the Tor protocol. Tor Browser is actually a modified version of Firefox which natively integrates the Tor protocol.

Then you should see a Tor Browser folder. Open it and launch the browser. A window appears.

Click on to log in directly if you want to start surf anonymously, but it is mandatory to go through Configurator if your ISP censors certain protocols or filters some traffic. In this case, you will have to go through a bridge, a gateway that will hide your point of entry into the network.

To activate this "obfuscation protocol" answer YES to the third question and use obfs3 as recommended. Finally click on Connect.

If you see "Congratulations ! This browser is configured to use Tor"is that you are free to surf the Internet wherever you want.


The browser's default search engine is lxquick and the modules HTTPS Everywhere et NoScript are activated. The first allows to add an SSL encryption layer to the HTTP protocol while the second disables all script on the browser. These are indeed a little too talkative and could reveal your identity using your real IP.

How to be anonymous and remain so?

  • Tor Browser is pre-configured to guarantee your anonymity. Do not modify the browser by adding plugins extensions, etc.
  • Connect only using the HTTPS protocol. The HTTPS Everywhere module forces sites to use this additional layer of encryption. Don't turn it off.
  • Do not open downloaded documents while online. DOC and PDF files in particular can betray your real IP when opened.
  • Protect yourself from the man-in-the-middle attack by using strong encryption while browsing the internet, sending email, chatting, ... etc.