Responsible for this webpage and blog as well as for the YouTube channels „Cryptography for everybody“, „Nils Retro Hobby Room“, and my personal YouTube channel “Nils Kopal” is:

Dr. Nils Kopal,
Universität Siegen
Institut für Wirtschaftsinformatik (FB3)
Kohlbettstr. 15
57068 Siegen


For all images used, care has been taken to ensure that they are royalty-free or publicly licensed, if possible. If you still do not see your license respected or would like to be linked, please feel free to write us a message. We will then remove the image or link you if you wish.


Referring to §7 par. 1 of the German Tele-Media Act (TMG), we are responsible as a service provider for our own content on this website. Beside the information we provide firsthand, this website contains links to third party websites. Before setting the links, we evaluated the content of these websites. However, as to §7 par. 2 of the TMG, we are not obligated to continous monitoring of that content. As soon as we find out that one of the websites we link to contains unlawful data, we will remove the associated link.

Under no circumstances are the involved universities (e.g. Siegen) responsible for the content of both this website and the links to other websites.