ed its per- formance under different scenarios. For example, Zhou and Hu [233] investigated computation efficiency maximization under wireless-powered MEC systems. It also compared two offloading schemes: joint and binary. An orthogonal frequency division multiple access (OFDMA)-based MEC system with computation efficiency maximization is proposed in [211], aiming for power and channel optimal allocation. Lastly, Zhang et al. [230] applied computation efficiency in an unmanned aerial vehicle (UAV)-enabled MEC offloading system, which also seeks for computation efficiency maximization. On the other hand, wireless offloading will unavoidably suffer from potential malicious activities due to the existence of eavesdropper. From physical layer information-theoretic perspective, achievable data rate with eavesdropper can be modeled as the difference of mutual information from transmitter to receiver and from transmitter to eavesdropper, regardless of security protection mechanisms. It can be considered as the lower bound of the actual data rate. This simplified analysis model has been adopted in various studies [30, 208]. This chapter highlights the following research contributions. 1. We consider a secure offloading model, which allows wireless transmission with the presence of eavesdroppers. We adopt the physical layer security model from information-theoretic perspective and is irrelevant of encryption schemes. 2. Computation efficiency is applied as the main metric, which finds the balance between maximizing computation bits and minimizing total energy consumption. 3. An iterative algorithm together with convex approximation is proposed to tackle a non-convex problem and has good convergence speed and performance. This chapter is organized as follows. Section 8.2 describes the secure offloading and computation model. An optimization problem is formulated in Section 8.3, followed by its approximation solution. Numeric results are presented in Section 8.4. Finally, Section 8.5 concludes this chapter. 5G and Beyond Wi