Secrecy of Communications in Data Transmission by Impulses with Unknown Moments of Appearance and Disappearance

We carried out a comparative analysis of the algorithms for detecting a rectangular impulse against Gaussian white noise under either authorized or unauthorized access to the transmitted data. We presupposed that for data transmission the binary communication system is used and that the useful information in the data is whether the signal is present or absent. The case is that unauthorized access by the outsider takes place in the situation when the signal parameters are completely or partially unknown. We then define the degree of the transmitted data secrecy by the secrecy ratio determining how highly the threshold signal-to-noise ratio increases when there is the unauthorized access instead of the authorized one.