CD-PHY: Physical layer security in wireless networks through constellation diversity

摘要

A common approach for introducing security at the physical layer is to relyon the channel variations of the wireless environment. This type of approach isnot always suitable for wireless networks where the channel remains static formost of the network lifetime. For these scenarios, a channel independentphysical layer security measure is more appropriate which will rely on a secretknown to the sender and the receiver but not to the eavesdropper. In thispaper, we propose CD-PHY, a physical layer security technique that exploits theconstellation diversity of wireless networks which is independent of thechannel variations. The sender and the receiver use a custom bit sequence toconstellation symbol mapping to secure the physical layer communication whichis not known a priori to the eavesdropper. Through theoretical modeling andexperimental simulation, we show that this information theoretic construct canachieve Shannon secrecy and any brute force attack from the eavesdropper incurshigh overhead and minuscule probability of success. Our results also show thatthe high bit error rate also makes decoding practically infeasible for theeavesdropper, thus securing the communication between the sender and receiver.