Efficient Physical-Layer Secret Key Generation and Authentication Schemes Based on Wireless Channel-Phase

Longwang Cheng,Wei Li,Boon-Chong Seet,Li Zhou,Dongtang Ma,Jibo Wei

doi:10.1155/2017/7393526

Abstract

Exploiting the inherent physical properties of wireless channels to complement or enhance the traditional security mechanisms has attracted prominent attention recently. However, the existing secret key generation schemes suffer from miscellaneous extracting procedure. Many PHY-layer authentication schemes assume that the knowledge of the shared key is preknown. In this paper, we propose PHY-layer secret key generation and authentication schemes for orthogonal frequency-division multiplexing (OFDM) systems. In the secret key generation scheme, to simplify the extracting procedure, only one legitimate party is chosen to probe the channel and quantize the measurements to obtain the preliminary key. The preliminary key is masked by the channel-phase after the mapping and before equalization and distributed to the other party. The final shared key is used for the PHY-layer authentication scheme in which random signals and the shared key masked by the channel-phase are exchanged at the PHY-layer. Then, a binary hypothesis test is formulated for authentication. Simulation results show that the proposed secret key generation scheme outperforms the existing schemes. For the PHY-layer authentication scheme, it is immune to various passive and active attacks and a high successful authentication rate is acquired even at low signal-to-noise ratio region.

Highlights

With the continuous development of the wireless communications, people pay more and more attention to the security issue
The major contributions of this paper are summarized as follows: (i) To simplify the secret key extraction procedure, we propose a secret key generation scheme based on the channel-phase response in which only one node is chosen to generate the preliminary key and further the preliminary key is masked by the channel-phase after mapping and before equalizing and distributed to the other node
We propose a secret key generation scheme based on the channel-phase response of orthogonal frequency-division multiplexing (OFDM) systems in frequency domain

Summary

Introduction

With the continuous development of the wireless communications, people pay more and more attention to the security issue. Many investigators pay attention to extract secret keys from received signal strength (RSS) [6,7,8,9], since the RSS is easy to acquire from the offthe-shelf wireless cards These methods suffer from scalability and low secret key generation rate (KGR) which is defined as the average amount of secret key bits produced in one measurement/second [10,11,12]. In [27], a PHY-layer phase challenge-response authentication scheme (PHY-PCRAS) was proposed It exploited the randomness and reciprocity of the channel-phase response to protect shared key from possible eavesdropping and achieve authentication. We propose PHY-layer secret key generation and authentication schemes for OFDM systems. Both schemes exploit the randomness and reciprocity of the channel-phase response that is very sensitive to the distance between the legitimate parties.

System Model

Secret Key Generation and Performance Analysis

PHY-Layer Authentication Scheme and Performance Analysis

Findings

Conclusion