Optimal Secrecy Capacity-DelayTradeoffin Large-ScaleMobileAdHocNetworks

Abstract—In this paper, we investigate the impact of informa-tion-theoretic secrecy constrainton the capacity and delay droppers whose location and channel state information (CSI)are both unknown.We assume legitimate nodes move according to the fast i.i.d.mobility pattern and each desires to communicate with one randomly selected destination node.There are also static eaves droppers located uniformly in the network and we assume the number of eaves droppers is much larger than that of legitimate nodes,i.e., .We propose a novel simple secure communication model,i.e.,the secure protocol model,and prove its equivalence to the widely accepted secure physical model under a few technical assumptions.Base dont he proposed model,a frame-work of analyzing the secrecy capacity and delay in MANETsis established.Give delay constraint ,we find that the optimal secrecy throughput capacity is ,where is the data rate of each link.We observe that:1)the capacity delay tradeoff is independent of the number of eaves droppers,which indicates that adding more eavesdroppers will not degenerate the of the legitimate network as long as ;2)the capacity delay tradeoff of our paperout performs the previous result in[11],where is the density of the eaves droppers.Throughout this paper,for functions and we denote if; if ; if there is a positive constant such that for sufficiently large ; if ;if both and hold.Besides,the order notation poly logarithmic factors for better readability.< final year projects >