Secrecy in wireless communication through closed-loop receiver de-synchronization

Abstract

A subset of the synchronization algorithms in a wireless receiver are responsible for tracking the phase and frequency of a digitally modulated signal. If variations of the phase in the signal are substantial, then the receiver might be unable to track them leading to inability to demodulate the data. In this paper we propose a method for improving the secrecy of wireless communication by ensuring that an arbitrary unauthorized receiver (URx) cannot track these phase and frequency changes but a legitimate (LRx) one can. This is accomplished by introducing artificial variations in the phase of a wireless transmitted signal that exceed the capabilities of a certain class of receivers. We explore receivers that employ closed-loop synchronization, namely a phase-lock loop (PLL) and we devise an artificial frequency variation pattern that can de-synchronize it. Our results indicate that with our method the bit error rate (BER) of an URx can be maintained at a pretty high level even for very favorable channel conditions.