Security-Reliability Tradeoff of Multi-hop Secure Communication Networks Using Fountain Codes and RIS-aided Cooperative Communication

This papers investigates security-reliability trade-off for multi-hop secure communication networks using Fountain codes (FCs) and reconfigurable intelligent surface (RIS). In the proposed scheme, a source sends Fountain packets to a destination through an established route, with presence of a passive eavesdropper. The destination and the eavesdropper attempt to collect Fountain packets to recover the source data. To enhance reliability of the data transmission at each hop, the RIS is deployed in the considered network, and the RIS is only used when the direct transmission at each hop is outage. This paper derives closed-form expressions of the end-to-end outage probability (OP) and intercept probability (IP) of the proposed scheme over Rayleigh fading channel. Simulations using Monte Carlo method are realized to verify the derivations. The results show that our scheme outperforms the conventional multi-hop secure communication scheme without using RIS.