Secrecy capacity of a Nakagami-m fading channel in the presence of cooperative eavesdroppers

Physical layer security helps enormously cryptography to improve the confidentiality of communications over wireless networks. Indeed, the secrecy capacity is used at the physical layer to ensure not only the security of communications but also to exploit efficiently the channel capacity. The principle of secrecy capacity is to characterize the maximum data transmission rate, that can be reached while the exchanged information is kept secret from a malicious entity. In this paper, we present a closed-form expression of outage probability and we specify the outage secrecy capacity of a Nakagami-m fading channel in the presence of cooperative correlated eavesdroppers performing the maximal ratio combining which helps the eavesdroppers to tap the maximum of the exchanged information between the transmitter and the legitimate receiver. Simulations results show that a raise in the number of the cooperative eavesdroppers degrades significantly the secrecy capacity of this communication system, moreover the correlation degree between the eavesdroppers has a negative impact on the communication confidentiality especially when it takes small values.