Enhancing Physical Layer Security Through Cooperation in Wireless Networks

Physical Layer Security (PLS) provides a promising complementary approach to cryptographic methods for protecting wireless communications from eavesdropping. This paper investigates secrecy enhancement through cooperative relaying and jamming in a wireless network with two legitimate users, one eavesdropper, and five potential relay nodes operating in amplify-and-forward mode. Three relay–jammer selection strategies are considered: random relay and jammer selection, best-SNR (signal-to-noise ratio) relay with random jammer selection, and best-SNR relay with a jammer chosen based on the strongest channel toward the eavesdropper. The secrecy performance of these strategies are evaluated in terms of secrecy rate and secrecy outage probability. The results demonstrate that intelligent relay and jammer selection can significantly improve PLS compared to random selection, highlighting the benefits of cooperation in secure wireless systems.