To put the topic of wireless security and privacy in context, one should look no further than the negative press that wireless networks and communications have received over the past decades in the area of security. Overall, securing wireless networks is distinctly different from securing “wired” networks. In part, this is due to the fact that wireless networks are open: open because the radio medium is a broadcast medium, which means adversaries can easily witness anything that is transmitted; and open because wireless devices are commodity items—adversaries can easily purchase low-cost wireless devices and, with little effort, use these platforms to launch attacks. Further complicating matters is the fact that there are many types of wireless networks (ranging from cellular to WiFi to WiMax to MANET/sensor networks to cognitive radios), and each of these networks have varying security and privacy requirements. Further complicating matters is the fact that, generally, wireless networks lack a trusted infrastructure, must inherently support mobility, and are subject to severe resource constraints (e.g. bandwidth and energy). http://www.apc.org/english/news/index.shtml?x=5038261
These basic properties have led to a broad array of security challenges that, although they might exist in wired networks, are far easier to perform in wireless networks. Some notable security threats that face wireless networks include attacks at the physical layer (e.g. jamming), attacks against network functionality (e.g. routing threats such as wormhole attacks), attacks against identity (e.g. Sybil attacks and identity spoofing), and collaborative attacks involving geographically distributed enemies. http://www.iep.gmu.edu/UnlicensedWireless.php
We will discuss the wireless technology of Wi-Fi, this is the trade name for a popular wireless technology used in home networks, mobile phones, video games and more. Wi-Fi is supported by nearly every modern personal computer operating system and most advanced game consoles
The purpose of Wi-Fi is to hide complexity by enabling wireless access to applications and data, media and streams. The main aims of Wi-Fi are to; Enabled device such as a PC, game console, cell phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points — called a hotspot — can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks, both architectures can operate in community networks.
In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Organizations and businesses such as airports, hotels and restaurants often provide free hotspots to attract or assist clients. Enthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access. Metropolitan-wide Wi-Fi (Muni-Fi) already has more than 300 projects in process. http://www.iep.gmu.edu/UnlicensedWireless.php
Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.
When wireless networking technology first entered the market many problems ensued for consumers who could not rely on products from different vendors working together. The Wi-Fi Alliance began as a community to solve this issue — aiming to address the needs of the end-user and to allow the technology to mature. The Alliance created the branding Wi-Fi CERTIFIED to reassure consumers that products will interoperate with other products displaying the same branding.
Many consumer devices use Wi-Fi. Amongst others, personal computers can network to each other and connect to the Internet, mobile computers can connect to the Internet from any Wi-Fi hotspot, and digital cameras can transfer images wirelessly.
Routers which incorporate a DSL-modem or a cable-modem and a Wi-Fi access point, often set up in homes and other premises, provide Internet-access and internetworking to all devices connected (wirelessly or by cable) to them. One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router.
As of 2007 Wi-Fi technology had spread widely within business and industrial sites. In business environments, just like other environments, increasing the number of Wi-Fi access-points provides redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fi implementations have moved toward “thin” access-points, with more of the network intelligence housed in a centralized network appliance, relegating individual access-points to the role of mere “dumb” radios. Outdoor applications may utilize true mesh topologies. As of 2007 Wi-Fi installations can provide a secure computer networking gateway, firewall, DHCP server, intrusion detection system, and other functions.
Threats posed by Wireless networks
The most common wireless encryption standard, Wired Equivalent Privacy or WEP, has been shown to be easily breakable even when correctly configured. Wi-Fi Protected Access (WPA and WPA2), which began shipping in 2003, aims to solve this problem and is now available on most products. Wi-Fi Access Points typically default to an “open” (encryption-free) mode. Novice users’ benefit from a zero-configuration device that works out of the box, but this default is without any wireless security enabled, providing open wireless access to their LAN. To turn security on requires the user to configure the device, usually via a software graphical user interface (GUI). Wi-Fi networks that are open (unencrypted) can be monitored and used to read and copy data (including personal information) transmitted over the network, unless another security method is used to secure the data. http://nocat.net/
In order to tackle the problems associated with securing wireless networks, one must step back and examine the full scope of the problem. Several interesting issues that warrant investigation in these topical areas are identified as follows:
Confidentiality: The wireless medium is easy to sniff, and as a result it is necessary to support encryption services and key management. Challenging issues arise related to establishing and maintaining keys for entities that have never had prior relationships.
Integrity: Wireless hardware/equipment need to be safe from modification—especially in light of the fact that they are small, portable and easily capable of being pilfered.
Forensics: Due to their accessibility, wireless networks will be the platform of choice for conducting attacks against the broader network infrastructure. An important question is how and whether the network should keep track of forensic evidence.
Privacy: The perpetual connectivity provided by wireless networks can also mean constant surveillance. As an example, through simple snooping one can monitor mobility and handoffs between networks. The implications of perpetual connectivity on aspects related to user privacy are an important issue that warrants investigation.
Location: Location is a new form of information provided by wireless systems that will facilitate new services. Location information needs to be trustworthy, and may be used to support more robust security mechanisms (e.g. location-oriented access control).
Intrusions: The pervasiveness of wireless networks should not mean that just anyone can participate without proper authorization. There have been numerous examples of security threats, such as rogue access points, that arise because of the drive for wireless connectivity and which represent threats to organizational (e.g. enterprise) security policies.
Availability: The value of a wireless network lies in its promise of ubiquitous connectivity. Unfortunately, wireless networks are also easy to “break” (e.g. jamming and denial of service). Developing more robust communication mechanisms, at all layers of the stack, will be important to assuring wireless connectivity.
Non-repudiation: One potential advantage of wireless communications arises from the fact that RF energy radiates. Although this implies that it is possible for an adversary to eavesdrop on communications, it also implies that wireless entities within the radio coverage pattern may serve as witnesses for the actions of the transmitter.
Resources: Wireless devices have unique resource considerations. In particular, energy and bandwidth are important factors to take into consideration when designing security solutions.
One serious issue with wireless network security is not just encryption, but access to the network (signal reception). With wired networking it is necessary to get past either a firewall or the security guard & locked doors. With wireless it is only necessary to get reception and spend as long as you want, comfortably out of (easy) reach of the network owner. Most business networks protect sensitive data and systems by attempting to disallow external access. Thus being able to get wireless reception (and thus possibly break the encryption) becomes an attack vector on the network as well.
Recreational logging and mapping of other people’s access points has become known as wardriving. It is also common for people to use open (unencrypted) Wi-Fi networks as a free service, termed piggybacking. Indeed, many access points are intentionally installed without security turned on so that they can be used as a free service. These activities do not result in sanctions in most jurisdictions; however legislation and case law differ considerably across the world. A proposal to leave graffiti describing available services was called warchalking. In a Florida court case, owner laziness was determined not to be a valid excuse. http://nocat.net/
Piggybacking is often unintentional. Most access points are configured without encryption by default, and operating systems such as Windows XP SP2 and Mac OS X may be configured to automatically connect to any available wireless network. A user who happens to start up a laptop in the vicinity of an access point may find the computer has joined the network without any visible indication. Moreover, a user intending to join one network may instead end up on another one if the latter’s signal is stronger. In combination with automatic discovery of other network resources (see DHCP and Zeroconf) this could possibly lead wireless users to send sensitive data to the wrong middle man when seeking a destination (see Man-in-the-middle attack). For example, a user could inadvertently use an insecure network to login to a website, thereby making the login credentials available to anyone listening, if the website is using an insecure protocol like HTTP, rather than a secure protocol like HTTPS.