Categories: All - security - mobility - noise

by nursyafeera azeera 11 years ago

974

wireless Network security

Information security is a multi-layered approach involving products, people, and procedures. This framework ensures the protection of devices that store, manipulate, and transmit data.

wireless Network security

Foundation of wireless security

Factor that make security increasingly difficult

– Speed of attacks – Sophistication of attacks – Attackers now detect weaknesses faster – Distributed attacks – User confusion

What is information security

Information security is achieved through a combination of three entities – Innermost layer consists of the products that provide the necessary security – Middle layer is people – Outmost layer consists of procedures
Information security protects devices that store, manipulate, and transmit the information

Wireless Advantages & disadvantages

Disadvantages
Radio frequency interference – Signals from other devices can disrupt wireless Health risks – High levels of RF can produce biological damage through heating effects – It is not known if or to what extent lower levels of RF might cause adverse health effects Security – Greatest disadvantage to wireless LANs – Attacks on wireless networks: denial-of-service, stealing passwords, altering messages
Advantages
Mobility – Primary advantage of wireless technology – Enables individuals to use a laptop computer that is always in contact with the network Easier and less expensive installation – Installing network cabling can be expensive – Significant time required to install network cabling – Wireless technologies allow creation of an office in a space where the traditional infrastructure doesn’t exist Increased reliability – Wireless LAN technology eliminates cable failures and increases the overall reliability of the network Disaster recovery – Hot site has all the equipment needed for an organization to continue running Generally run by a commercial disaster recovery service – Cold site provides office space but the customer must provide and install all the equipment – Many businesses use cold sites and WLANs as a major piece of their disaster recovery plan

Wireless in our world

health care
The health care industry has embraced wireless technology to improve patient care Wireless LAN point-of-care computer systems – Allow medical staff to access and update patient records immediately – Verify that medication is being administered to the correct patient in the correct dosage
education
WLANs are ideal for colleges and schools • Educational institutions were early users of WLANs • Wireless LAN connections offer teachers and students an important degree of freedom – Teachers create classroom presentations on laptops – Can access the school network wirelessly from almost any location • Most schools publish maps showing the location of wireless access points CWSP Guide to Wireless Security 17
travel
Travel industry is a leader in adopting wireless technologies – Most airports provide wireless access hotspots – Some airports use wireless technology to keep track of passenger luggage • Wireless PDAs now replace walkie-talkies • WLAN technology is used to communicate with the aircraft – Once it has parked or is taxiing on the ground • WLAN technologies are not restricted to airplanes
bussiness
“Flatter” organizations Business – Employees are involved in team meetings that occur away from their desks • Wireless technology – Has dramatically changed how and where business meetings take place • Has made the meetings more focused and productive • Wireless LANs benefits – Increased productivity, time/financial savings Voice over wireless LAN (VoWLAN) – Emerging wireless technology – Uses the existing data WLAN to make and receive telephone calls – VoWLAN devices can forward business calls to their mobile phones during regular business hours

What attacker can do?

- Steal personal data - View wireless transmissions - With freely available wireless packet sniffer - Inject malware - Download harmful content - Cause loss of equipment - Cause violation of an ISP agreement - Identify “weak link” users

WLAN (Wireless LAN) Architecture

WLAN may include several access points
Dependent upon number of stations – Maximum number varies: 10-100
Infrastructure WLAN
Stations communicate with access point • Not directly with each other Access point requires sufficient power, strategic placement
Wireless access point (WAP)
Accepts wireless signals from multiple nodes • Retransmits signals to network – Base stations, wireless routers, wireless gateways
Ad hoc WLAN
Wireless nodes transmit directly to each other – Use wireless NICs • No intervening connectivity device – Poor performance • Many spread out users, obstacles block signals

Signal degradation

Noise
Significant problem • No wireless conduit, shielding
Attenuation
Signal weakens • Moving away from transmission antenna Correcting signal attenuation • Amplify (analog), repeat (digital) Noise
Fading
Variation in signal strength • Electromagnetic energy scattered, reflected, diffracted

signal propagation

obstacle effect signal travel, signal may
Pass through them – Be absorbed into them – Be subject to three phenomena • Reflection: bounce back to source • Diffraction: splits into secondary waves • Scattering: diffusion in multiple different directions
LOS (line-of-sight)
Signal travels in straight line • Directly from transmitter to receiver

wireless spectrum

Spans 9 KHz and 300 GHz
- Data, voice communication - Arranged by frequencies which is from lowest to highest frequency
Continuum of electromagnetic waves