Improving secrecy for multi‐relay multi‐eavesdropper wireless systems through relay selection

Abstract

In this paper, we consider a cooperative relay network consisting of a source, a destination and multiple decode-andforward relays in the presence of multiple eavesdroppers, which intend to tap confidential messages transmitted by both the source and relays. We propose both the so-called secrecy maximisation oriented relay selection (SMORS) and multirelay oriented relay selection (MRORS) schemes to improve the physical layer security of wireless communications. In the SMORS scheme, a single relay with the maximal secrecy rate is selected among all the decode-and-forward relays to forward the source signal. By contrast, in the MRORS scheme, the relays that succeed in decoding the source signal will be employed to simultaneously forward their decoded signals to the destination. We analyse the intercept probability of the SMORS and MRORS schemes as well as the traditional max-min relay selection scheme. It is shown that the proposed MRORS scheme outperforms the SMORS and max-min relay selection schemes in terms of the intercept probability. Additionally, it is shown that with an increasing number of eavesdroppers, the intercept performance of wireless communications degrades, which can be well addressed using the SMORS and MRORS schemes through increasing the number of relays. By contrast, increasing the number of relays has little impact on the intercept probability for the conventional max-min relay selection scheme Transactions on Emerging Telecommunications Technologies.

Leakage rate–based untrustworthy relay selection

“…The system stays active between −10 dB and −20 dB; beyond 20 dB, the system outage performance cannot be improved and saturates. These observations are consistent with the analytical derivations (22) and the derived asymptotic CDF expression. Figure 3 extends the analysis and provides the performance comparison of the HD, FD, and HRS strategies in TWR mode.…”

“…However, the obtained performance improvements with the FD-based selection strategy is at negligible levels. These observations are consistent with the analytical derivations (18), (20), (22), and derived asymptotic CDF expressions. Figure 4 presents the outage performance of the HRS in OWR mode.…”

“…Ding et al 22 considers a cooperative relay network, where the source terminal conducts information exchange with the help of a single/multiple DF-based HD relaying terminal in the presence of a multiple eavesdroppers. In addition, they 22 also propose secrecy maximization-oriented relay selection, which is based on the maximal secrecy rate, and multirelay-oriented relay selection, which is based on the relay terminals that successfully decoding the source signal, to improve the PHY security. Cai et al 23 consider a similar system model structure as in the work of Ding et al 22 Unlike Ding et al, 22 Cai et al 23 consider a single eavesdropper in the system model structure.…”

“…In addition, they 22 also propose secrecy maximization-oriented relay selection, which is based on the maximal secrecy rate, and multirelay-oriented relay selection, which is based on the relay terminals that successfully decoding the source signal, to improve the PHY security. Cai et al 23 consider a similar system model structure as in the work of Ding et al 22 Unlike Ding et al, 22 Cai et al 23 consider a single eavesdropper in the system model structure. In addition, Cai et al 23 also consider a secrecy rate maximization-based relay selection strategy.…”

Asymptotic Bound of Secrecy Capacity for MIMOME‐Based Transceivers: A Suboptimally Tractable Solution for Imperfect CSI

“…In [19], taking into account various receiver arrangements for MIMOME transceivers over Nakagami-m fading channels, SOP was precisely computed. In [20], it was proven that the intercept probability does not rely on Eave' numbers in a cooperative-based network; instead, it relies specifically upon the number of relays. Asymptotic bounds for the outage probability defined for the secrecy rate and the achievable diversity were explored in [21].…”