Intelligent Reflective Surface-Assisted MEC Securely Calculates Offloading Policy

To enhance the security in the computational offloading process of Mobile Edge Computing (MEC) systems, this paper proposes a physical layer secure transmission scheme based on Intelligent Reflecting Surface (IRS) assistance. In this scheme, IRS is added to facilitate the task transfer between the user and the MEC server, while suppressing eavesdroppers from eavesdropping on user information, thus achieving a secure computing offload for the system. In order to maximize the safe transmission rate of the system, a flow-form optimization algorithm based on alternating optimization and conjugate gradient is designed to obtain the users transmit power as well as the phase shift of the IRS. Based on this, the computational offload rate of users and the computational resources of MEC servers are optimized by heuristic algorithms to minimize the computational offload delay of MEC systems while ensuring secure transmission. Simulation results show that the proposed scheme can reduce the total computational offload delay while guaranteeing secure transmission of the MEC system compared with other benchmark schemes and traditional artificial noise assisted schemes.