Tutorial 7 Wireless Networking and Security. XP Objectives Explore the history of wireless...

Tutorial 7

Wireless Networking and Security

XPXPXPObjectives• 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 2

XPXPXPObjectives• 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


XPXPXPEvolution 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


XPXPXPEvolution of Wireless Networks• 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


XPXPXPEvolution of Wireless Networks• 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


XPXPXPEvolution of Wireless Networks• 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


XPXPXPEvolution of Wireless Networks• 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


XPXPXPEvolution of Wireless Networks• 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


XPXPXPWireless 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


XPXPXPWireless Local Area Networking


XPXPXPWireless Local Area Networking• 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


XPXPXPWireless Local Area Networking• 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


XPXPXPWireless Local Area Networking• 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


XPXPXPWireless 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


XPXPXPWireless Mesh Networks


XPXPXPPersonal 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


XPXPXPInfrared 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


XPXPXPBluetooth• 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


XPXPXPBluetooth


XPXPXPBluetooth• 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


XPXPXPComparing Wi-Fi Standards with Bluetooth


XPXPXPWireless 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


XPXPXPMetropolitan 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


XPXPXPMetropolitan Area Networking: WiMAX• 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


XPXPXPMetropolitan Area Networking: WiMAX


XPXPXPMetropolitan Area Networking: WiMAX• 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


XPXPXPUsing Wireless Devicesto 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


XPXPXPSecurity 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


XPXPXPWireless 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


XPXPXPWired 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


XPXPXPWired Equivalent Privacy


XPXPXPWired 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


XPXPXPWi-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


XPXPXPMAC 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


XPXPXPDisabling 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


XPXPXPDisabling 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


XPXPXPChanging 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


XPXPXPSecurity Checklist for Installing a Wireless Router or Access Point


XPXPXPSecurity 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


XPXPXPProtecting 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


XPXPXPProtecting 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


XPXPXPEvil 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


XPXPXPEvil 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


XPXPXPSecurity 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


XPXPXPSecurity Concerns for Bluetooth Devices• 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


XPXPXPSecurity Concerns for Bluetooth Devices• 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


XPXPXPSecurity Concerns for Bluetooth Devices• 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


XPXPXPSecurity Concerns for Bluetooth Devices• 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


XPXPXPSummary• 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. XP Objectives Explore the history of wireless...

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