Tutorial 7 - Wireless Networking and Security

Tutorial 7 Wireless Networking and Security

Objectives
Explore the history of wireless communication
Learn about Wi-Fi and wireless mesh networks
Investigate technologies used in personal area networks
Learn about wireless wide area networks and WiMAX
Investigate wireless devices and wireless business plans that let you access the Internet
New Perspectives on The Internet, Seventh Edition

Objectives
Investigate security concerns of wireless networks
Evaluate different wireless encryption methods
Investigate security concerns of wireless devices
Learn how to protect the data stored on a wireless device
Learn about the different types of attacks on wireless devices
Learn about the different types of attacks on Bluetooth devices

Evolution of Wireless Networks
When you connect to your Internet service provider, you’re creating a wired connection
A wireless connection occurs when data is transferred to another location without the use of any wires
In 1994, carriers created digital networks, or Personal Communication Service (PCS ), where data was carried in bits at a rate of up to 144 Kbps

1999 saw the introduction of the first “wireless” connections to the Internet
Personal digital assistant (PDA): handheld computer that can send and receive wireless telephone and fax calls, act as a personal organizer, perform calculations, store notes, and download Web pages formatted for handheld devices
The wireless Internet has expanded to include different hardware devices, networks, and other options

Cell phones were one of the first wireless connections to transfer a person’s voice
Text messaging occurs over second-generation wireless systems , or 2G wireless
Short Message Service (SMS) lets you send text messages of up to 160 characters over a 2G wireless network to a wireless phone

Some handheld computers use Infrared technology to “beam” information from one source to another without the use of wired connections
Over 60 major US markets have new 3G wireless systems (third-generation wireless) in places. Some European countries are building and licensing 3G wireless systems
3G wireless systems offer data transfer rates of up to 2 Mbps and constant connections
Bandwidth and cost are two obstacles for getting 3G wireless systems going in the United States

The conversion from 2G to 3G wireless requires the carriers to invest in technology to make the change
Many carriers have transformed and upgraded their existing networks by creating 25G wireless systems
There isn’t a single network standard
A wireless device is usually manufactured to work only on a single type of network, because different networks use different frequencies in the radio spectrum
If you choose a wireless carrier with a 25G network, for example, you will not be able to receive a signal in an area with only a 2G or a 3G network because your device operates on a different frequency

35G wireless networks use a new network protocol called Universal Mobile Telephone Service (UMTS), which is an extension of the existing 3G network, to provide network connections of up to 10 Mbps
Fourth-generation wireless networks ( 4G wireless )
Also called 3G wireless and beyond networks
4G technology is expected to bring network connection speeds of up to 100 Mbps and deliver high quality audio and video to connected devices

Wireless Local Area Networking
Wireless fidelity ( Wi-Fi ): trademarked name of the Wi-Fi Alliance (WFA) that specifies the interface between a wireless client and a base station or between two wireless clients
Wireless local area network (WLAN): network in which devices use high frequency radio waves instead of wires to communicate
Wi-Fi operates in the 24 GHz radio spectrum, which is the same spectrum used by cordless phones, garage door openers, microwave ovens, and other devices
Because this spectrum is unlicensed, it is free
3G wireless spectrum needs to be licensed

Wireless Local Area Networking New Perspectives on The Internet, Seventh Edition

Three of the most widely used standards for WLANs are 802.11a, 802.11b, 802.11g, and 802.11n
Transfer rate: speed at which data is transmitted from an access point (or base station) to the wireless device
Access point: hardware device with one or more antennae that permits communication between wired and wireless networks so wireless clients can send and receive data
Range: physical distance between the access point and the wireless device

Wi-Fi usually refers to the 802.11b standard which is the specification on which most Wi-Fi devices operate
Dual band access point: makes it possible to connect devices configured for two different Wi-Fi standards to the same access point
Multiple band access point: makes it possible to connect any wireless device to the same access point
Wi-Fi is often used as an alternative in an office building or other area in which you might find a traditional wired local area network. It can be used where wiring cannot be installed

Notebook computers and other wireless devices must have Wi-Fi compatible hardware installed in them to send and receive data with the network
Once you have a network interface card or other Wi-Fi compatible device, you can connect to the WLAN via that device, provided that it is physically within the area covered by the network
If you position enough access points within the appropriate range of each other, the WLAN can grow to cover an entire office complex or geographic area

Wireless Mesh Networks
Wireless mesh network: commonly used to extend the reach of Wi-Fi hotspots to an enterprise, such as a university campus, hotel, airport terminal, convention center, sports arena, or a large office building
A wireless mesh network is a series of wireless nodes
More effective and efficient at covering large areas with wireless connections because each node is wirelessly connected to the network

Wireless Mesh Networks New Perspectives on The Internet, Seventh Edition

Personal Area Networking
Personal area networking : refers to the wireless network that you use to connect personal devices to each other
There are two major types of personal area networks:
Infrared
Bluetooth

Infrared Technology
Infrared Data Association ( IrDA ): group dedicated to developing low-cost, high-speed wireless connectivity solutions
Using infrared technology, you can wirelessly beam information from one device to another compatible device using Infrared light waves
This technology is used with PDAs, notebook computers, printers, phones, and other peripheral devices
A disadvantage is the lack of software products that can handle the transfer The devices and the software that runs them must be compatible with each other

Bluetooth
Bluetooth : technology that provides short-range radio links between personal computers, handheld devices, wireless phones, headsets, printers, and other electronic devices
For devices without chipsets that enable them to receive Bluetooth radio waves, you can purchase an adapter to enable use with other Bluetooth devices
Bluetooth doesn’t need an access point for communication; devices communicate with each other automatically
Bluetooth isn’t really “owned” by any specific manufacturer or group

Bluetooth New Perspectives on The Internet, Seventh Edition

Bluetooth
Using Bluetooth technology, you can synchronize and share data between as many as eight Bluetooth compatible devices within the specified range at a rate of up to 3 Mbps
A collection of devices connected via Bluetooth technology is called a piconet. A piconet can connect two to eight devices at a time
You can use Bluetooth-enabled devices to transfer files, listen to music playing on a computer through a headset, print documents, or connect your notebook computer to the Internet using a wireless phone that is in your desk drawer or briefcase

Comparing Wi-Fi Standards with Bluetooth New Perspectives on The Internet, Seventh Edition

Wireless Wide Area Networking
Wireless device connections let you access the Internet on a PDA, wireless phone, or notebook computer from anywhere in the world without a wired connection
WLAN provides a wireless connection to a network, but devices must be within the stated boundary of the WLAN
In 25G and 3G wireless systems, wireless wide area networking ( WWAN ) makes it possible to access the Internet from anywhere within the boundaries of the wireless network to which you are connected

Metropolitan Area Networking: WiMAX
WiMAX ( Worldwide Interoperability for Microwave Access ): uses 802.16 wireless network standard being developed for use in metropolitan areas
Metropolitan area network ( MAN ): provides wireless broadband Internet access via radio signals in the 2 to 11 GHz and 10 to 66 GHz radio spectrum, with a range of up to 31 miles and speeds of up to 70 Mbps
When multiple WiMAX towers are connected to each other, WiMAX has the potential to solve some of the geographical and speed limitations of wired networks and other wireless networks, including Wi-Fi

WiMAX provides broadband Internet connections at the same speed as DSL and cable, through wireless radio connections
WiMAX works by connecting a WiMAX tower to an ISP that provides the Internet service
The WiMAX towers are connected to each other via radio signals
WiMAX transmitters send the signal to homes and businesses that have WiMAX receivers
Transmitters can be located up to 31 miles from the towers
Businesses can plug the WiMAX receiver into their existing local area networks to provide high-speed Internet access to all of their connected devices

Metropolitan Area Networking: WiMAX New Perspectives on The Internet, Seventh Edition

VoIP ( Voice over Internet Protocol ): converts audio signals to digital packets so that you can use a broadband wired or wireless Internet connection to make local and long distance telephone calls
Because WiMAX can support many types of data transmissions, it is also used for VoIP
Most experts predict that all new desktop and notebook computers and wireless devices will eventually have built-in 802.16 cards

Using Wireless Devices to Access the Internet
The technology and standards that dictate what you can accomplish with a wireless device change on a daily basis
New standards emerge, new hardware is created, and new ways of connectivity arrive
Select a wireless solution that has the locations in which the technology will be used in its network coverage area and that supports the features you plan to use

Security Concerns for Wireless Networks
The following list of threats are common to all wireless networks:
Attacks that prevent the use of a device or decrease the network’s bandwidth
Intercepting information sent over a wireless network
Hacking into a wireless device to gain entry to its data or functions
Stealing the identity of an access point to gain access to its connected users’ devices
Viruses, spyware, and other security threats sent in the form of files
Using information entered by the user into a wireless device to steal logins and other sensitive information

Wireless Encryption Methods
Encryption : process of coding information so that it is not readable by devices or people who do not have the secret key used to return the information back to its original, readable state
By default, most wireless networks are unsecured
Many home and small business networks are never secured and are vulnerable to various kinds of attacks
There are many wireless encryption methods that provide different levels of protection for wireless networks

Wired Equivalent Privacy
Wired Equivalent Privacy (WEP) : security protocol for wireless LANs (using Wi-Fi) that works by encrypting data sent over the network
When WEP is enabled, it encrypts the data sent over the network with a 64-bit or 128-bit key, that is entered by the user
Network key also called a passphrase
The encryption slows down the network somewhat because of the time it takes to encrypt and decrypt the messages

Wired Equivalent Privacy New Perspectives on The Internet, Seventh Edition

Wired Equivalent Privacy
Depending on the equipment used and how much time and money a hacker has, it can take a very long time to decipher an intercepted message encrypted with a 64-bit key, and even longer to decipher an intercepted message encrypted with a 128-bit key
Another vulnerability of WEP encryption is the fact that the key used to encrypt the data you are sending is sent over the network prior to the actual data being encrypted, and this same key is used to encrypt every data packet

Wi-Fi Protected Access
Wi-Fi Protected Access (WPA) : standard developed by the Wi-Fi Alliance in 2003 to address some of the inherent weaknesses in WEP
WPA uses a preshared key to encrypt data
Individual packets are encrypted with different keys
One drawback is that all devices in the network need to use WPA

MAC Address Filtering
Each manufacturer of network interface cards adds a unique number, called a Media Access Control address (MAC Address)
Usually printed on the card
Designate the devices that you want to allow to connect to the network
If you enable MAC address filtering for a wireless router or access point, then it will only accept connections from the devices with the MAC addresses that you entered

Disabling SSID Broadcast
When a wireless router or access point sends out its signal, it also broadcasts its service set identifier (SSID) as a way of identifying the network’s name
Most manufacturers of wireless routers and access points use the manufacturer name or the word “default” as the default SSID
For public wireless networks, sending out the SSID is necessary

Disabling SSID Broadcast
For home networks, sending out the SSID is not necessary, because you already know the network’s name
Disabling the SSID broadcast of the network makes the network invisible to roaming devices
If you change the default name of the wireless router or access point, you also prevent unknown users from detecting
Wardriving: driving through a neighborhood with a wireless-enabled notebook computer with the goal of locating houses and businesses that have wireless networks in order to gain access to them your network

Changing the Default Login
When you install a wireless router or access point for the first time, the device is configured with a default user name and password
Use your computer to access the device’s settings and configure it to work as desired
One of the most serious mistakes that home users make when installing a wireless network is the failure to change the default login for the device
If you haven’t implemented any other security, your wireless network is visible and easy to access

Security Checklist for Installing a Wireless Router or Access Point New Perspectives on The Internet, Seventh Edition

Security Concerns for Wireless Devices
The most basic security concern for the owner of a wireless device is theft or loss
If you have a PDA or other device that also stores data such as passwords that you use to connect to online banking or your Internet connection, you might be losing much more than the device itself

Protecting the Data on a Wireless Device
A wireless device is vulnerable to certain kinds of attacks to the data it stores
Over-the-shoulder attacks: unauthorized person uses his or her physical proximity to your device to attempt to get your login information, passwords, or other sensitive data while you are working
Most security experts advise against activities such as online banking, checking email, and online shopping in public places

Protecting the Data on a Wireless Device
Opt for a wired Ethernet connection whenever possible
Connecting to the Internet with a wired connection eliminates the wireless threats to your device
Setting a password on your device is another way to protect it

Evil Twin Attacks
In an evil twin attack , also sometimes called a café latte attack because the attack often occurs at coffeehouses, a hacker gathers information about an access point and then uses that information to set up his own computer to use the real access point’s signal to impersonate the access point
As customers use their devices to pick up and connect to the access point, they are unaware that they are actually connecting to the hacker’s computer

Evil Twin Attacks
When you use one of the many free public hotspots for wireless computing, the data you send over the network is not usually encrypted or secure
This data is subject to hackers using sniffer programs to illegally monitor activity on the wireless network

Security Concerns for Bluetooth Devices
The usual range of a Bluetooth device is about 10 to 30 feet, and up to 300 feet
This range makes it possible for you to use a wireless headset with a cell phone or to print documents without the need for a cable
Three security problems common to Bluetooth devices are bluejacking, bluesnarfing, and bluebugging

Bluejacking : bluejacker sends an anonymous message displayed as a text message to a Bluetooth device in an attempt to surprise the owner, express a comment or opinion, or contact the owner to make a social connection
Mostly harmless because the victim’s device is not breached; it is only sent a message
To protect a Bluetooth device from a bluejacking attack, you can disable the device’s Bluetooth feature so that its signal is invisible (also called undiscoverable mode) to other users

Bluesnarfing : hacker with special software is able to detect the signal from a Bluetooth device and gain access to its data without the owner’s knowledge
More serious security problem
After gaining access, the hacker is able to access data stored on the device, such as the contact list or calendar, connect to the Internet, listen in on phone calls, and send email messages from the victim’s device
To protect a Bluetooth device from a bluesnarfing attack, you can set the device to undiscoverable mode
Newer Bluetooth devices are not subject to bluesnarfing attacks because this vulnerability has been fixed

Bluebugging : hacker gains access to the device and all of its functions without the owner’s consent
Worst of the security threats to Bluetooth devices
Bluebugging attack lets the hacker use the device to make phone calls, access data, and use the Internet
Some hackers set up phone numbers with per-minute charges to the caller and use bluebugging to dial those numbers while the device is in range

Most manufacturers of Bluetooth devices have released patches to fix the security flaw that makes bluebugging possible
Bluesnarfing and bluebugging can only occur within the range of the Bluetooth device and on older devices and those not updated with the latest security patches
Both of these attacks are less likely when the Bluetooth device is undiscoverable to other users

Summary
Different types if wireless networks, wireless network standards, and wireless devices
Different types of security threats and solutions for wireless networks and wireless devices
Wireless network and wireless device protection from security threats

Tutorial 7 - Wireless Networking and Security

by dpd on Oct 27, 2008

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