Secure Wireless Communications via Cooperative Transmitting

Toni Draganov Stojanovski,Ninoslav Marina

doi:10.1155/2014/760175

Abstract

Information-theoretic secrecy is combined with cryptographic secrecy to create a secret-key exchange protocol for wireless networks. A network of transmitters, which already have cryptographically secured channels between them, cooperate to exchange a secret key with a new receiver at a random location, in the presence of passive eavesdroppers at unknown locations. Two spatial point processes, homogeneous Poisson process and independent uniformly distributed points, are used for the spatial distributions of transmitters and eavesdroppers. We analyse the impact of the number of cooperating transmitters and the number of eavesdroppers on the area fraction where secure communication is possible. Upper bounds on the probability of existence of positive secrecy between the cooperating transmitters and the receiver are derived. The closeness of the upper bounds to the real value is then estimated by means of numerical simulations. Simulations also indicate that a deterministic spatial distribution for the transmitters, for example, hexagonal and square lattices, increases the probability of existence of positive secrecy capacity compared to the random spatial distributions. For the same number of friendly nodes, cooperative transmitting provides a dramatically larger secrecy region than cooperative jamming and cooperative relaying.

Highlights

Information-theoretic secrecy has attracted a significant interest in recent years due to its possible applications in wireless communications and the growing significance of wireless networks
Wyner [1] first introduced the concept of wiretap channel in 1975. He has determined that a message can be transmitted reliably from a transmitter to a receiver without revealing any information on the message to the eavesdropper provided that the transmitter operates at rates smaller than the secrecy capacity
They established the secrecy capacity region for this channel in which the message intended for the legitimate receiver is kept private

Summary

Introduction

Information-theoretic secrecy has attracted a significant interest in recent years due to its possible applications in wireless communications and the growing significance of wireless networks. He has determined that a message can be transmitted reliably from a transmitter to a receiver without revealing any information on the message to the eavesdropper provided that the transmitter operates at rates smaller than the secrecy capacity. The secret key is securely and cooperatively transmitted to the receiver (without being divulged to the eavesdroppers) using informationtheoretic secrecy if the secrecy capacity is positive for the communication channel between at least one transmitter and the receiver. Once the secret key is exchanged, the legitimate parties can start communicating at the maximum data rate since their communication channel is cryptographically protected, achieving computational secrecy [8].

Network Model

Cooperative Transmitting

Conclusion