Many people have a fallacious feeling of being anonymous when surfing the Internet. But, ordinary Internet communication on the network layer is by default not anonymous because of the usage of identifying characteristics like Internet Protocol (IP) or Media Access-Control (MAC) addresses. So, if no additional measures are taken, an adversary can easily observe which participants of a network communicate with each other. But, anonymity on the network layer of communication systems can be achieved by the use of anonymizing techniques. Based on anonymous communication on the network layer, necessary identification and authenticity of users can still be implemented on a higher layer, e.g., with privacy-enhancing identity management [8].