# Robust Secrecy via Aerial Reflection and Jamming: Joint Optimization of Deployment and Transmission

## TL;DR

This paper proposes a robust method to enhance wireless security using aerial RIS and jamming, optimizing deployment and transmission to maximize secrecy under imperfect channel information.

## Contribution

It introduces a joint optimization framework for aerial RIS deployment and transmission strategies to improve worst-case secrecy in wireless networks.

## Key findings

- Aerial RIS and jamming significantly improve security performance.
- Optimized deployment enhances worst-case secrecy rates.
- The proposed method outperforms baseline approaches in simulations.

## Abstract

Reconfigurable intelligent surfaces (RISs) are recognized with great potential to strengthen wireless security, yet the performance gain largely depends on the deployment location of RISs in the network topology. In this paper, we consider the anti-eavesdropping communication established through a RIS at a fixed location, as well as an aerial platform mounting another RIS and a friendly jammer to further improve the secrecy. The aerial RIS helps enhance the legitimate signal and the aerial cooperative jamming is strengthened through the fixed RIS. The security gain with aerial reflection and jamming is further improved with the optimized deployment of the aerial platform. We particularly consider the imperfect channel state information issue and address the worst-case secrecy for robust performance. The formulated robust secrecy rate maximization problem is decomposed into two layers, where the inner layer solves for reflection and jamming with robust optimization, and the outer layer tackles the aerial deployment through deep reinforcement learning. Simulation results show the deployment under different network topologies and demonstrate the performance superiority of our proposal in terms of the worst-case security provisioning as compared with the baselines.