Wireless LAN Security Analysis and Improvement

Abstract

Due to the broadcast nature of radio propagation, the wireless air interface is open and accessible to both for authorized and illegitimate users. This is different from a wired networks, where communicating devices are physically connected each other through cables and a node without direct connection is unable to access the network. The open nature of communications medium makes wireless transmissions more vulnerable than wired communications to malicious attacks, including both passive eavesdropping for data interception and active jamming for disrupting legitimate transmissions. Therefore, this work is motivated to examine the security vulnerabilities and threats imposed by the inherent open nature of wireless communications and to devise efficient counter measure mechanisms for improving the wireless network security. We first summarized the security requirements of wireless networks, including their authenticity, confidentiality, integrity, and availability. Next, a comprehensive overview of security attacks encountered in wireless networks is presented in view of the network protocol architecture, where the potential security threats are discussed at each protocol layer. We also provided a survey of the existing security protocols and algorithms that are adopted in the existing wireless network standards. Then, we discussed the state of the art in physical-layer security, which is an emerging technique of securing the open communications environment against eavesdropping attacks at the physical layer. Several physical-layer security techniques are reviewed and compared, including information-theoretic security, artificial-noise-aided security, security-oriented beamforming, and physical-layer key generation approaches. Additionally, we discussed the integration of physical-layer security into existing authentication and cryptography mechanisms for further securing wireless networks. Our framework is based on a hybrid of layered security based on physical primitives: collaborative jamming and the upper layer security. Notably, it can avoid the use of shared secrets, while providing a more secure system which relies on physical layer’s unique features that is more secure than conventional cryptosystem