Contribution estimation of malicious external modulation into phase of multipath signal

Abstract

© 2019 IEEE. Randomness of channel in wireless communication systems can be used to generate identical copies of secret encryption key at both sides of radio link. Such possibility is based on the channel reciprocity and on randomness of radio propagation paths between the legitimate users, which are unknown to possible adversaries. Users generate identical encryption keys from measurements of random parameters of multipath signal (e.g. carrier phase). In this paper, we investigate experimentally a possibility of malicious manipulation over the received multipath signal if a hostile transmitter emits an imitating pseudo signal, which contains some deterministic imposing modulation. In this case, the adversary forces the phase of the signal received by legal users to follow the external modulation known to him. Experimental dependence of the cross-correlation level between the phase measurements of the legal users and adversary on the power of imposing pseudo signal is presented.