Tor Browser is a web browser based on Mozilla Firefox but configured to protect your privacy.

Ihre Verbindungen über das Tor Netzwerk zu senden, ist nicht genug, um sie komplett zu schützen, während sie im Internet surfen.

• Cookies können benutzt werden, um sie zu tracken und auf anderen websites zu identifizieren.
• Sicherheitslücken in JavaScript wurden in der Vergangenheit benutzt um, den Tor Browser zu deanonymisieren. (https://arstechnica.com/information-technology/2013/08/attackers-wield-firefox-exploit-to-uncloak-anonymous-tor-users/).

Das ist auch der Grund, warum Tor Browser alle Arten von Sicherheitsfeatures in den Browser eingebaut hat.

Some frequently asked questions about Tor Browser can be found in the FAQ.

Proxy server refusing connections

The following error message in Tor Browser means that Tails is not yet connected to the Tor network:

The proxy server is refusing connections

Make sure that you are:

1. Connected to a local network
2. Connected to the Tor network

AppArmor confinement, downloading, and uploading files

Tor Browser in Tails is confined with AppArmor to protect the system and your data from some types of attacks against Tor Browser. As a consequence, Tor Browser in Tails can only read and write to a limited number of folders.

• Sie können Dateien vom Tor Browser in den Tor Browser Ordner speichern, der sich im Home-Verzeichnis befindet. Der Inhalt dieses Ordners wird verschwinden, sobald Sie Tails herunterfahren.

• Wenn Sie Dateien mit dem Tor Browser hochladen möchten, kopieren Sie diese zuerst in diesen Ordner.

• If you turned on the Persistent Folder feature of the Persistent Storage, you can also use the Persistent/Tor Browser folder to download and upload files from Tor Browser. The content of the Persistent/Tor Browser folder is saved across different working sessions.

Hiding that you are using Tor Browser

It is impossible to hide to the websites that you visit that you are using Tor, because the list of exit nodes of the Tor network is public.

That is why many more websites ask you to solve a CAPTCHA when using Tor Browser.

The anonymity provided by Tor Browser works by making all users look the same to make it impossible to know who is who among the millions of users of Tor Browser.

Tails tries to make it as difficult as possible for websites to distinguish Tails users from other users of Tor Browser. If it was possible for a website to determine whether you are a user of Tor Browser inside or outside of Tails, this would provide a little bit more information about you and reduce your anonymity.

The websites that you visit can retrieve a lot of information about your browser, whether it's Tor Browser or a regular browser. This information is called the fingerprint of the browser and includes the name and version of the browser, the size of the window, the time zone, the available fonts, etc.

To make it difficult to distinguish Tails users from other users of Tor Browser, Tor Browser in Tails tries to provide the same information as Tor Browser on other operating systems.

A difference is that Tails includes the uBlock Origin extension, which removes advertisements. If an attacker can determine that you are not downloading the advertisements that are included in a webpage, that could reveal that you are a Tails user.

HTTPS encryption with HTTPS Everywhere

Using HTTPS instead of HTTP encrypts your communications with the website and prevents the Tor exit node from intercepting your communications.

For example, here is how the browser looks when we try to log in to an email account at riseup.net, using their webmail interface:

Notice the padlock icon on the left of the address bar saying "mail.riseup.net". Notice also the address beginning with "https://" (instead of "http://"). These are the indicators that an encrypted connection using HTTPS is being used.

When you are sending or retrieving sensitive information (like passwords), you should try to only use services providing HTTPS. Otherwise, it is very easy for an eavesdropper to steal whatever information you are sending, or to modify the content of a page on its way to your browser.

HTTPS Everywhere is a Firefox extension included in Tor Browser. It is produced as a collaboration between The Tor Project and the Electronic Frontier Foundation. It encrypts your communications with a number of major websites. Many sites on the web offer some limited support for encryption over HTTPS, but make it difficult to use. For example, they might default to unencrypted HTTP, or fill encrypted pages with links that go back to the unencrypted site. The HTTPS Everywhere extension fixes these problems by rewriting all requests to these sites to HTTPS.

To learn more about HTTPS Everywhere, you can see:

• die HTTPS Everywhere Homepage
• die HTTPS Everywhere FAQ

Protection against dangerous JavaScript

Having all JavaScript disabled by default would disable a lot of harmless and possibly useful JavaScript, and might render many websites unusable.

That is why JavaScript is enabled by default but Tor Browser disables all potentially dangerous JavaScript. We consider this as a necessary compromise between security and usability.

Security level

You can change the security level of Tor Browser to disable browser features as a trade-off between security and usability. For example, you can set the security level to Safest to disable JavaScript completely.

The security level is set to Standard by default which gives the most usable experience.

To change the security level, click on the icon on the right of the address bar and choose Advanced Security Settings….

Tor circuit

Click on the padlock in the address bar to show the Tor circuit that is used to connect to the website in the current tab, its 3 relays, their countries, and IP addresses.

The last relay in the circuit, the one immediately above the destination website, is the exit relay. Its country might influence how the website behaves.

Click on the New Circuit for this Site button to use a different circuit.

You can use Onion Circuits to get more detailed information about the circuits being used.

New Identity feature

To switch to a new identity, choose  ▸ New Identity.

The New Identity feature of Tor Browser:

• Schließt alle Tabs.
• Clears the session state including cache, history, and cookies.
• Beendet alle bestehenden Webverbindungen und erstellt neue Tor-Verbindungen.

For more details, see the design and implementation of the Tor Browser.

NoScript to have even more control over JavaScript

Tor Browser includes the NoScript extension to:

• Protect from more JavaScript attacks. For example, cross-site scripting (XSS) attacks.
• Allow you to disable JavaScript completely on some websites only.

For more information, you can refer to the NoScript website and features.

Letterboxing

The letterboxing feature of Tor Browser helps to prevent websites from identifying your browser based on the size of its window. Without letterboxing, websites could use the size of the browser window to track visitors or weaken your anonymity.

The letterboxing feature of Tor Browser works by adding gray margins to the browser window when the window is resized. The webpage remains as close as possible to the desired size without revealing the actual size of the window.