Wirtschaftsuniversität Wien Magisterarbeit - SemanticLab

indirect route to its destination. The nodes in the network are called “onion routers”
because they uncover a layer of the “onion” (the traffic-package) to receive instructions
where the traffic should be relayed to next - at the end, the package arrives at its final
destination in plain text [OR09]. The Tor software makes use of this principle and can
be obtained directly at the Tor project website at http://www.torproject.org. There are
ready to install bundles available at the website of the project. These bundles also install
all software necessary to use Tor with Firefox (including the “Torbutton” extension).
With the “Tor Map” tool one can see all onion routers (that is nodes) in the Tor network
and which route the traffic took for example while browsing “www.google.com” as shown
in Figure 5.9. Although the Tor network may provide a huge amount of anonymity, its
disadvantage clearly is the slow speed of the network due to a lack of bandwidth. While
conducting tests, the bandwidth available decreased from approx. 9MB/s without Tor
to approx. 0-14kb/s (!) with Tor which makes normal surfing impossible.
Figure 5.9.: Map of onion routers and the route between two nodes used to access
“www.google.com”
5.3.3. Switchproxy
Besides these sophisticated solutions, there are of course also simple Firefox extensions
for managing different proxies. One example is Switchproxy which easily enable users
to switch proxy with two mouse clicks, for example to change from the ISPs’ proxy to
the proxy of ones’ university to access the digital library without having to change the
connection settings from Firefox manually.
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