The paper describes two projectsof Deparment of Communication and Information Systems of University of Defencein Brno. The first one is the Crypto Mouse. It is a computer mouse emulating OpenPGP crypto card. It contains ARM micro-controller with Gnuk software installed. Unlike ordinary solution using card and crypto card reader this solutionis inconspicious. Signing, validating, encrypting and decrypting of data can be used by mouse. Gnuk is free software so anyone can download the code and verify it. The second project isthe Trojan USB Device. This Trojan USB Device can look like ordinary USB flash drive but in reality it can be for example a fake keyboard. When this Trojan USB Device is plugged into USB port it is activated and started to "write" prepared words or even run prepared commands. For example it starts the web browser and surf to the prepared web site, starts the Command Promt and run the command format C: to format hard drive or collects the private data and send them by email or transfer by ftp to the Trojan USB Device owner. Both pojects are used in computer security lessons at the Department of Communication and Infomation Systems.