Evaluation of a wireless physical security method for flying objects based on the frequency selectivity of the propagation channel

Air-to-air and air-to-ground communication have been used to interchange data between and from/to different flying objects, respectively, supporting a wide range of applications and protocols. Encryption algorithms are used to secure communications, relying often on pseudo random number generators. Emerging physical layer security methods avoid such number generators and their drawbacks. They rely on the multipath characteristics of the wireless signal that is assumed to be unique and determined by the environment surrounding the communication entities. In this work, an algorithm for generating a security key for encrypting communications within a network is evaluated by analysing the air-to-air/-ground radio propagation channel, which is applied to a case of study of two flying objects.