Enhancing PHY Security of Cooperative Cognitive Radio Multicast Communications

Abstract

Abstract-In this paper, we propose a cooperative approach to improve the security of both primary and secondary systems in cognitive radio multicast communications. During their access to the frequency spectrum licensed to the primary users, the secondary unlicensed users assist the primary system in fortifying security by sending a jamming noise to the eavesdroppers, while simultaneously protect themselves from eavesdropping. The main objective of this work is to maximize the secrecy rate of the secondary system, while adhering to all individual primary users' secrecy rate constraints. In the case of active eavesdroppers and perfect channel state information (CSI) at the transceivers, the utility function of interest is nonconcave and the involved constraints are nonconvex, and thus, the optimal solutions are troublesome. To solve this problem, we propose an iterative algorithm to arrive at least to a local optimum of the original nonconvex problem. This algorithm is guaranteed to achieve a Karush-Kuhn-Tucker solution. Then, we extend the optimization approach to the case of passive eavesdroppers and imperfect CSI knowledge at the transceivers, where the constraints are transformed into a linear matrix inequality and convex constraints, in order to facilitate the optimal solution.

Reliability‐Security Trade‐Off Analysis of Cognitive Radio Networks with Jamming and Licensed Interference

“…Interference power constraint Thermal noise Reliability-security trade-off analysis [14] x x [17] x x x [18][19][20][21] x x x [22] x x [23] x [24] x x x 1.1. Related Works.…”

“…Therefore, the connection outage constraint together with ignored thermal noise considerably simplifies information securing capability analysis in [23]. The authors in [24] design a beamforming vector at the multiantenna unlicensed source to maximize the minimum secrecy rate of the unlicensed network while guaranteeing the minimum secrecy rate of the licensed network and satisfying maximum transmit power constraint for cognitive multicast communications. Besides beamforming the legitimate signals, the source transmits the jamming signal together with them to further secure information transmission.…”

“…Besides beamforming the legitimate signals, the source transmits the jamming signal together with them to further secure information transmission. However, [24] ignores interference power constraint. Table 1 summarizes typical characteristics considered in [14,[17][18][19][20][21][22][23][24] with an emphasis that reliabilitysecurity trade-off analysis is not implemented there.…”

“…In contrast to [14,[17][18][19][20][21][22][23][24] where jamming signal and legitimate signal are merged and concurrently broadcasted by an unlicensed transmitter, [25][26][27][28][29][30][31][32] suggest new techniques to prevent eavesdroppers from stealing confidential information in CRNs where jamming signal and legitimate signal are transmitted by two different users. To be more specific, jamming signal and legitimate signal are separately transmitted by two different UUs to guarantee LUs' communication securely while maintaining QoS of UUs [25].…”

“…The above literature survey [14,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] shows that reliability-security trade-off analysis of CRNs, where legitimate signal and jamming signal are simultaneously transmitted by two different unlicensed transmitters, under interference from licensed transmitter, maximum transmit power constraint, interference power constraint, and thermal noise, has not been reported in any open literature. We aim to perform this analysis with threefold contributions:…”