A Survey of Wireless Network Security

GFGDFGDFGDFG ABSTAAAAR Wireless networking is inherently insecure. From jamming to eavesdropping, from man-in the middle to spoofing, there are a variety of attack methods that can be used against the users of wireless networks. Modern wireless data networks use a variety of cryptographic techniques such as encryption and authentication to provide barriers to such infiltrations. However, much of the commonly used security precautions are woefully inadequate. They seem to detract the casual sniffer, but are unable to stop the powerful adversary. In this article, we look into the technology and the security schemes in IEEE 802.11, cellular and Bluetooth wireless transport protocols. We conclude that the only reliable security measure for such networks is one hat is based on application level security such as using a VPN.The wireless communication technology also acquires various types of security threats. This paper discusses a wide variety of attacks in WSN and their classification mechanisms and different securities available to handle them including the challenges faced. KeywordsWireless Sensor Network; Security Goal; Security Attacks; Defensive mechanisms; Challenges S. Gopalakrishnan, International Journal of Computer Science and Mobile Computing, Vol.3 Issue.1, January2014, pg. 53-68 © 2014, IJCSMC All Rights Reserved 54 INTRODUCTION of Wireless Technology Wireless technologies, in the simplest sense, enable one or more devices to communicate without physical connections without requiring network or peripheral cabling. Wireless technologies use radio frequency transmissions as the means for transmitting data, whereas wired technologies use cables. Wireless technologies range from complex systems, such as Wireless Local Area Networks (WLAN) and cell phones to simple devices such as wireless headphones, microphones, and other devices that do not process or store information. They also include infrared (IR) devices such as remote controls, some cordless computer keyboards and mice, and wireless hi-fi stereo headsets, all of which require a direct line of sight between the transmitter and the receiver to close the link. WIRELESS NETWORKS Wireless networks serve as the transport mechanism between devices and among devices and the traditional wired networks (enterprise networks and the Internet). Wireless networks are many and diverse but are frequently categorized into three groups based on their coverage range: Wireless Wide Area Networks (WWAN), WLANs, and Wireless Personal Area Networks (WPAN). WWAN includes wide coverage area technologies such as 2G cellular, Cellular Digital Packet Data (CDPD) and Global System for Mobile Communications (GSM), and Mobitex. WLAN, representing wireless local area networks, includes 802.11, HiperLAN, and several others. WPAN represents wireless personal area network technologies such as Bluetooth and IR. All of these technologies are “tether less”—they receive and transmit information using electromagnetic (EM) waves. Wireless technologies use wavelengths ranging from the radio frequency (RF) band up to and above the IR band. The frequencies in the RF band cover a significant portion of the EM radiation spectrum, extending from 9 kilohertz (kHz), the lowest allocated wireless communications frequency, to thousands of gigahertz (GHz). As the frequency is increased beyond the RF spectrum, EM energy moves into the IR and then the visible spectrum. Wireless networks allow devices to be moved about with varying degrees of freedom and still maintain communication with each other. They also offer greater flexibility than cabled networks and significantly reduce the time and resources needed to set up new networks and allow for ad hoc networks to be easily created, modified or torn down. There are many forms of wireless networks. One way of categorizing wireless networks is to consider the relative range and complexity of each type of network. For example: WIRELESS PERSONAL AREA NETWORK (WPAN) – a small-scale wireless network that requires little or no infrastructure and operates within a short range. A WPAN is typically used by a few devices in a single room instead of connecting the devices with cables. Examples include print services or enabling a wireless keyboard or mouse to communicate with a computer. WIRELESS LOCAL AREA NETWORKS (WLANS) are groups of wireless networking nodes within a limited geographic area, such as an office building or campus, that are capable of radio communications. WLANs are usually implemented as extensions to existing wired local area networks to provide enhanced user mobility. S. Gopalakrishnan, International Journal of Computer Science and Mobile Computing, Vol.3 Issue.1, January2014, pg. 53-68 © 2014, IJCSMC All Rights Reserved 55 WIRELESS METROPOLITAN AREA NETWORKS (WMANS) can provide connectivity to users located in multiple facilities generally within a few miles of each other. Many WMAN implementations provide wireless broadband access to customers in metropolitan areas. WIRELESS WIDE AREA NETWORKS (WWANS) connect individuals and devices over large geographic areas. WWANs are typically used for mobile voice and data communications, as well as satellite communications. WIRELESS LAN: WLANs allow greater flexibility and portability than do traditional wired local area networks (LAN).Unlike a traditional LAN, which requires a wire to connect a user’s computer to the network, a WLAN connects computers and other components to the network using an access point device. An access point communicates with devices equipped with wireless network adaptors; it connects to a wired Ethernet LAN via an RJ45 port. Access point devices typically have coverage areas of up to 300 feet(approximately 100 meters). This coverage area is called a cell or range. Users move freely within the cell with their laptop or other network device. Access point cells can be linked together to allow users to even “roam” within a building or between buildings. AD HOC NETWORKS: Ad hoc networks such as Bluetooth are networks designed to dynamically connect remote devices such as cell phones, laptops, and PDAs. These networks are termed “ad hoc” because of their shifting network topologies. Whereas WLANs use a fixed network infrastructure, ad hoc networks maintain random network configurations, relying on a master-slave system connected by wireless links to enable devices to communicate. In a Bluetooth network, the master of the piconet controls the changing network topologies of these networks. It also controls the flow of data between devices that are capable of supporting direct links to each other. As devices move about in an unpredictable fashion, these networks must be reconfigured on the fly to handle the dynamic topology. The routing that protocol Bluetooth employs allows the master to establish and maintain these shifting networks. LAYERED SECURITY FOR WIRELESS NETWORKS: A layered approach to wireless security can provide a high degree of protection and leverage existing network security investments. The layered approach consists of the following four levels: [1]  Wireless deployment and policy  Wireless access control  Perimeter security  Application security When implemented, as discussed below, the layered approach can make a WLAN more secure than a typical wired network by centralizing points of access, implementing manageable device-level security and governing internal access with firewall-level S. Gopalakrishnan, International Journal of Computer Science and Mobile Computing, Vol.3 Issue.1, January2014, pg. 53-68 © 2014, IJCSMC All Rights Reserved 56 policies. Security professionals speak in terms of work factor, which is an important concept when implementing layered security. A network with a high work factor is difficult to break into, while a network with a low work factor can be compromised more easily. If hackers determine that the network has a high work factor, which is inherent in the layered approach, they will soon move on to those that are less secure. LEVEL1-WIRELESS DEPLOYMENT AND POLICY Best practices for wireless deployment and policy are: Deploy the minimum number of WAPs needed for adequate Coverage. Set WAP broadcast power to the lowest practical level.  Verify broadcast coverage in and around facility. Maintain policies for:  Installation of WAPs  NIC operational mode  WLAN user-group access, including employees, visitors