The Unmanned Systems (US) are used in a wide range of military and civil applications in aerial, underground, on the ground and under water environment. Large investments, particularly in robotics, in micro - electronics, in Communications Networks, in Information Theory and in Artificial Intelligence reinforce this trend.The functionality of the Unmanned Systems and their applications are absolutely dependent on the Cyber – Systems, which are used for the collection, the storage, the processing and the communication of relevant data. While huge efforts for the Security and Data Protection of Cyber - Systems are being held, the lack of a strict modeling of this threat and severe risk analysis leads to general solutions regarding the protection of systems, which are not always effective. Thus, it is necessary to develop a holistic approach in order to protect these Data and Systems from threats.In the present thesis the security requirements of Unmanned Vehicles, the elements of modeling and the means by which the threats achieve their goals are presented. Finally, the technology of UAVs related to Jamming and anti-jamming systems is presented.