Secrecy Capacity of Diffusive Molecular Communication Under Different Deployments

Currently, the physical layer security is considered as one of the most suitable security techniques in Diffusive Molecular Communication (DMC) because of ease to implement. A recent piece of literature has presented the Secrecy Capacity (SC) of DMC system under the rectangular deployment. To evaluate the information capacity (IC) and thereby SC using the Concentration Greens Function (CGF) in the molecular communication depends on the biological structures of tissues. In this paper, we have investigated the analytical expressions of IC under both the Biological Cylindrical Deployment (BCD) and Biological Spherical Deployment (BSD). Therefore, the analytical expressions of IC have been employed to derive the mathematical expressions of SC under the BCD and BSD environment. Further, the SC is analyzed as a function of distance/radius considering the power and/or bandwidth as the parameter. In addition, the effect of distance of authentic receiver on SC is also explored. It is observed that irrespective of the deployments, the distance of the authentic receiver illustrates predominant effect on the value of SC. The proposed analysis is useful in the implementation of DMC under different tissues structures. The numerically simulated results show close agreement with the theoretical background.