Secrecy Performance of Terahertz Based Systems Over Fluctuating Two-Ray Fading

Ensuring security in terahertz (THz)-based communications is the prime objective in 6G-based systems. This paper investigates the information-theoretic security of a THz-based communication system over fluctuating two-ray (FTR) fading. We analyze the system from a partial secrecy regime and utilize fractional equivocation to obtain closed-form expressions for the generalized secrecy outage probability (GSOP), the average fractional equivocation (AFE), and the average information leakage rate (AILR) metrics. Further, the effect of fading parameters, such as the fading severity index, the average power ratio factor, and the dominant waves similarity index, on the secrecy metrics are also analyzed. Numerical results show that with increasing average power ratio factor, the system’s secrecy is compromised from the AFE and AILR perspectives, whereas from the GSOP perspective, increasing the average power ratio factor results in secrecy improvement. Concurrently, degradation in the system’s secrecy in terms of the GSOP is observed for increasing similarity index and fractional equivocation values. However, from AFE and AILR metrics perspective, increasing the similarity index results in secrecy improvement. Finally, the confidential information rate effect on the system’s secrecy is also analyzed. Increasing the confidential information rate leads to secrecy compromisation, as observed by increasing GSOP and AILR and decreasing AFE.