Relay Secrecy in Wireless Networks with Eavesdropper

Anonymous monitoring of transmissions in a wireless network by eavesdroppers can provide critical information about the data flows in the network. It is, therefore, necessary to design network protocols that maintain secrecy of routes from eavesdroppers. In this work, we present a mathematical formulation of route secrecy when eavesdroppers observe transmission epochs of nodes. We propose a scheduling technique to provide complete secrecy of routes, and based on that, characterize achievable rate regions for two hop source destination pairs with a common relay under two PHY models : transmitter directed and receiver directed spread spectrum signaling. The results are also extended to the case when an additional constraint on packet loss is imposed. Index Terms Network Security, Secrecy, Multiple Access, Packet Loss.