Day of Submission: 18.06.2012

Abstract

We declare that the work submitted in this thesis is our own, except as acknowledged in the text and footnotes, and has not been previously submitted for a degree at the Technical University of Darmstadt or any other institution. We further declare that we have not used any other than permitted reference sources or materials. Day by day, a huge number of information flows through the internet. But, how many of innocent internet users are really aware of the danger that could come with this information exchange itself? Communication, which is a very basic need for mankind since the very earlier phases of the evolution, took as expected its own top place on this very fast developing highway as well. What most of the users do not know is that the communication through internet is not secure, if they do not use necessary protection tools. Unfortunately many of these tools are very complicated to be employed by ordinary users. But are there no solutions, which allow communication via internet in some secure and usable way? As we searched for answers to this simple question, we saw that there are some other studies which also tried to find the similar answers. We also found out that there are some others wh