SlideShare a Scribd company logo
SEMINARS
OF
SEMISTER – I
[ YEAR 2013-2014 ]

NAME: SHITAL KATKAR

TOPIC: Wifi Technology

SIGNATURE:________________

1
SEMINAR – I
WIFI Technology

2
CONTENTS:
 Wifi Technology
 Radio waves
 Flavors Of Wifi
 Applications
 Advantages
 Limitation
 Conclusion

3
INTRODUCTION
Technology is making rapid progress and is making many things easier.As the
innovative thinking of persons is increasing day-by-day,new methods for wireless
networking has been evolved of which our present topic Wi-Fi is the most accepted
technology.
Wi-Fi, an acronym for Wireless-Fidelity which is the wireless way to handle
networking. It is also known as 802.11 networking. The big advantage of WiFi is its
simplicity. You can connect computers anywhere in your home or office without the need
for wires. The computers connect to the network using radio signals, and computers can be
up to 100 feet or so apart.

RADIO WAVES

This is the Electromagnatic spectrum. Range of Radio Wave is 3 kHz to 300 GHz.
Radio waves are mainly use for communication. Wifi uses radio technology.

4
FLAVOURS OF WIFI
IEEE 802.11, is a set of standards to allow different devices to communicate
wirelessly. It is created by the IEEE (pronounced eye-triple-e) LAN/MAN Standards
Committee.
•

IEEE 802.11b

•

IEEE 802.11a

•

IEEE 802.11g

•

IEEE 802.11n

IEEE 802.11 b


Appear in late 1999



Operates at 2.4GHz radio spectrum



11 Mbps (theoretical speed) - within 30 m Range



4-6 Mbps (actual speed)



100 -150 feet range



Most popular, Least Expensive



Interference from mobile phones and Bluetooth devices which can reduce the
transmission speed.

IEEE 802.11 a


Introduced in 2001



Operates at 5 GHz (less popular)



54 Mbps (theoretical speed



15-20 Mbps (Actual speed)



50-75 feet range



More expensive



Not compatible with 802.11b
5
IEEE 802.11 g


Introduced in 2003



Combine the feature of both standards (a,b)



100-150 feet range



54 Mbps Speed



2.4 GHz radio frequencies



Compatible with ‘b’



Use OFDM Technology
(OFDM is a orthogonal frequency division multiplexing. It is basically a method of
encoding digital data on multiple carrier frequencies)

IEEE 802.11 n


Introduced in 2009



Uses multiple antennas that function in a "MIMO" mode ( multiple-input multipleoutput)



2.5 GHz and 5 GHz radio frequency



150 Mbps speed



Range up to 230 feet indoor

6
APPLICATIONS OF WIFI
These are the placese where wifi is used
o Home
o Small Businesses or SOHO
o Large Corporations & Campuses
o Health Care
o Wireless ISP (WISP)
o Travelers
Many devices can use wi-fi e.g. personal computers, video-game consoles,
smartphones, some digital cameras, tablet computers and digital audio players. These can
connect to a network resource such as the Internet via a wireless network access point.

ADVANTAGES OF WI-FI
1. Wi-Fi is a core technology in GPS Industries Applications.
2. Wi-Fi technology available in hotels, airports, etc., will be more inclined to bring
laptop with us when traveling for personal reasons.
3. Frees network devices from cables, allows for a more dynamic network to be grown.
1. Changes the way people live, communicate, work and play.
4. Many reliable and bug-free Wi-Fi products on the market
2. 5.It helps to become more productive at home, like online shopping and banking;
5. Wi-Fi technology allows getting out of home office and working in other rooms.

7
DISADVANTAGES OF WI-FI
1. 1.The 802.11b and 802.11g flavors of Wi-Fi use the 2.4 GHz spectrum, which is
crowded with other devices such as Bluetooth, microwave ovens, cordless phones,
or video sender devices, among many others.
2. 2.Power consumption is fairly high compared to other standards, making battery life
and heat a concern.
3. 3.It is not always configured properly by users.

CONCLUSION
As Wi-Fi is now shipped in millions of products and deployed in millions of homes,
business and hotspots worldwide, the technology has moved beyond the realm of a
computer feature. Wi-Fi has fast become a cultural phenomenon.

8
SEMINAR – II
WIFI Technology

9
CONTENTS:
 Elements of WIFI
 Walkie Talkie Network
 WIFI's Radio Technology
 Working of WIFI
 Communication in WIFI
 Adding WIFI to a computer
 WIFI's network topologies
 Conclusion

10
Elements of a WI-FI Network


Access Point (AP) - The AP is a wireless LAN transceiver or “base station” that can
connect one or many wireless devices simultaneously to the Internet.



Wi-Fi cards - They accept the wireless signal and relay information. They can be
internal and external. (e.g PCMCIA Card for Laptop and PCI Card for Desktop PC)



Safeguards - Firewalls and anti-virus software protect networks from uninvited users
and keep information secure.

Wi-Fi’s Walkie-Talkie Network
To understand the wire less technology let us consider a pair of Walkie-Talkies.These
are small radios that can transmit and receive radio signals.When we talk into a WalkieTalkie, our voice is picked up by a microphone, encoded onto a radio frequency and
transmitted with the antenna. Another Walkie-Talkie can receive the transmission with its
antenna, decode our voice from the radio signal and drive a speaker.
Simple Walkie-Talkies like this transmit at a signal strength of about 0.25 watts, and
they can transmit about 500 to 1,000 feet.
If we want to connect two computers together in a network using Walkie-Talkie
technology. Equip each computer with a Walkie-Talkie. Give each computer a way to set
whether it wants to transmit or receive. Give the computer a way to turn its binary 1s and
0s into two different beeps that the walkie-talkie could transmit and receive and convert
back and forth between beeps and 1s/0s. This would actually work. The only problem would
be that the data rate would be very slow. Walkie-talkie is designed to handle the human
voice.So it is not being able to send very much data in this way(may be 1,000 bits per
second).

11
Wi-Fi's Radio Technology



WiFi radios that work with the 802.11b and 802.11g standards transmit at 2.4 GHz,
while those that work with the 802.11a standard transmit at 5 GHz. Normal walkietalkies normally operate at 49 MHz. The higher frequency allows higher data rates.



WiFi radios use much more efficient coding techniques that also contribute to the
much higher data rates. For 802.11a and 802.11g, the technique is known as
orthogonal frequency-division multiplexing (OFDM). For 802.11b, it is called
Complementary Code Keying (CCK).



The radios used for WiFi have the ability to change frequencies. 802.11b cards can
transmit directly on any of three bands, or they can split the available radio
bandwidth into dozens of channels and frequency hop rapidly between them. The
advantage of frequency hopping is that it is much more immune to interference and
can allow dozens of WiFi cards to talk simultaneously without interfering with each
other.

WORKING OF WIFI
The most important items which makes Wi-Fi working in the laptop or desktop are
 Radio Signals
 Wi-Fi Card which fits in your laptop or computer.
 Hotspots which create Wi-Fi Network.

12
o A Wi-Fi hotspot is created by installing an access point to an internet
connection.
o An access point acts as a base station.
o When Wi-Fi enabled device encounters a hotspot the device can then
connect to that network wirelessly.
o A single access point can support up to 30 users and can function within a
range of 100 – 150 feet indoors and up to 300 feet outdoors.
o Many access points can be connected to each other via Ethernet cables to
create a single large network.

Radio Signals:


Radio Signals are the keys which make WiFi networking possible. These radio signals
transmitted from Wi-Fi antennas are picked up by WiFi receivers such as computers
and cell phones that are equipped with WiFi cards. Whenever a computer receives
any of the signals within the range of a WiFi network which is usually 300 - 500 feet
for antennas, the WiFi card will read the signals and thus create an internet
connection between the user and the network without the use of a cord.



Access points which consist of antennas and routers are the main source which
transmit and receive radio waves.



Antennas work stronger and have a longer radio transmission with a radius of 300500 feet which are used in public areas while the weaker yet effective router is more
suitable for homes with a radio transmission of 100-150 feet.

Wi-Fi Cards:
You can think WiFi card as being an invisible cord that connects your computer to the
antenna for a direct connection to the internet.


WiFi cards can be external or internal, meaning that if a WiFi card is not installed in
your computer, you may purchase a USB antenna attachment and have it externally
connect to your USB port, or have an antenna-equipped expansion card installed
directly to the computer. For laptops, this card will be a PCMCIA card in which you
insert to the PCMCIA slot on the laptop.

13
Wi-Fi Hotspots


A Wi-Fi hotspot is created by installing an access point to an internet connection. The
access point transmits a wireless signal over a short distance . typically covering
around 300 feet. When a Wi-Fi enabled device, such as a Pocket PC, encounters a
hotspot, the device can then connect to that network wirelessly.



Most hotspots are located in places that are readily accessible to the public, like
airports, coffee shops, hotels, book stores and campus environments. 802.11b is the
most common specification for hotspots worldwide. The 802.11g standard is
backwards compatible with .11b but .11a uses a different frequency range and
requires separate hardware such as an a, a/g, or a/b/g adapter. The largest public
Wi-Fi networks are provided by private internet service providers (ISPs) that charge a
fee for users to connect to the internet.

COMMUNICATION IN WI-FI

Data exchange in Wi-Fi can be summarized into three phases:
Phase I: Where data is prepared for transmission; it is encoded; changed into frames (digital
signals are sent in frames for better QoS). The frequency for data transmission is also chosen
depending upon the technique used to send the signals wirelessly.
Phase II: Where data is transmitted with air as the medium of wave transmission

14
Phase III: Where data is received, decoded, acknowledged and then used.
All of these phases apply some of the popular digital communications spread spectrum
techniques for signal multiplexing (FHSS, Infrared, OFDM etc.), make use of security
methods (WEP, WPA).

Adding WiFi to a Computer
Many new laptops come with a Wi-Fi card built in. It is also easy to add a Wi-Fi card to an
older laptop or a desktop PC. The process is


Take a 802.11a, 802.11b or 802.11g network card. 802.11g has the advantage of
higher speeds and good interoperability on 802.11b equipment.


For a laptop, this card will normally be a PCMCIA card that slide into a
PCMCIA slot on laptop. Or take a small external adapter and plug it into a USB
port.



For a desktop machine, take a PCI card & install inside the machine, or a small
external adapter and connect to the computer with a USB cable.



Install the card



Install the drivers for the card



Find an 802.11 hotspot



Access the hotspot.

15
WI-FI NETWORK TOPOLOGIES
1. AP-based topology (Infrastructure Mode)
2. Peer-to-peer topology (Ad-hoc Mode)
3. Point-to-multipoint bridge topology

AP-based topology (Infrastructure mode)



The client communicate through Access Point.



BSA-RF coverage provided by an AP.



ESA-It consists of 2 or more BSA.



ESA cell includes 10-15% overlap to allow roaming.

Peer-to-peer TOPOLOGY



AP is not required.



Client devices within a cell can communicate directly with each other.



It is useful for setting up of a wireless network quickly and easily.

16
Point-to-multipoint bridge TOPOLOGY



This is used to connect a LAN in one building to a LANs in other buildings even if the
buildings are miles apart. These conditions receive a clear line of sight between
buildings. The line-of-sight range varies based on the type of wireless bridge and
antenna used as well as the environmental conditions.

Conclusion


Wi-fi is a simple, cost-effective way to connect to the Internet , Without the need to
physically connecting wires.



Hotspot s a geographic area setup in any public location, and has a readily accessible
wireless network



Security is a huge challenge for Wi-Fi Networks, many Security Techniques are used
to improve it.

The Future of Wi-Fi

This is the graph of Hotels offering Wi-Fi.
The future of Wi-Fi is very bright. Its growing in popularity because of decreasing cost and
the freedom it gives to users.
17
SEMINAR – III
WIFI Security

18
CONTENTS:
 Need of security
 Wi-Fi Security Threats
 Security requirements
 Security Techniques
 Wi-Fi security tips
 Conclusion

19
Security is essential part of Wifi Technology. Wi-Fi can be less secure than wired
connections (such as Ethernet) because an intruder does not need a physical connection.

Why security is more of a concern in wireless?


no inherent physical protection


physical connections between devices are replaced by logical associations



sending and receiving messages do not need physical access to the network
infrastructure (cables, hubs, routers, etc.



ƒ broadcast communications


wireless usually means radio, which has a broadcast nature



transmissions can be overheard by anyone in range – anyone can generate
transmissions,


• which will be received by other devices in range



• which will interfere with other nearby transmissions and may
prevent their correct reception (jamming).

Wi-Fi Security Threats
Wireless technology doesn’t remove any old security issue, but introduces new ones
o Eavesdropping
o Man-in-the-middle attacks
o Denial of Service

20
Eavesdropping
Eavesdropping is the act of secretly listening to the private conversation of others without
their consent.


Easy to perform, most impossible to detect



By default , everything is transmitted in clear text



-No secuirty offered by the transmission medium



Different tools available on the internet



-Network sniffers, protocol analysers




-Username, passwds,content...

-Passwd collectors

With the right equipment, it’s possible to eavesdrop traffic from few kilometres
away

Man In The Middle Attack
An attack where a user gets between the sender and receiver of information and sniffs any
information being sent.


Attacker spoofs a disassociate message from the victim



The victim starts to look for a new access point, and the attacker advertises his own
AP on a different channel, using he real Aps MAC address



The attacker connects to the real



AP using victim’s MAC address

21
Denial of Service
Denial-of-service attack (DoS attack) is an attempt to make a machine or network resource
unavailable to its intended users.


Attack on transmission regency used





Frequency jamming
Not very technical, but works

Attack on MAC layer





Spoofed deauthentication / disassociatin messages
Can target on specific user

Attacks on higher layer protocol(TCP/IP protocol)


SYN Flooding

Wireless communication security requirements


Confidentiality – messages sent must be encrypted



Authenticity – origin of messages received must be verified



Replay detection – freshness of messages received must be checked



Integrity – modifying messages on-the-fly (during radio transmission) is not
so easy, but possible, Integrity of messages received must be verified



ƒ Access control – access to the network services should be provided only to
legitimate entities

SECURITY TECHNIQUES


Open/free/Unsecured (No Password)



WEP (Wired Equivalent privacy)



WPA (Wifi Protected access)



WPA II
22
Unsecured/Open
Leaving your Wi-Fi unsecured is synonymous with leaving your front door wide open,
so anyone could simply walk in. Leaving your Wi-Fi unsecured also transmits data packets
between users and the router in unencrypted format, which makes these data packets easy
to intercept and read.

WEP (Wired Equivalent Privacy)
WEP (Wired Equivalent Privacy) was the default encryption protocol introduced in
the first IEEE 802.11 standard back in 1999. It is based on the RC4 encryption algorithm,
with a secret key of 40 bits or 104 bits being combined with a 24-bit Initialisation Vector (IV)
to encrypt the plaintext message M and its checksum – the ICV (Integrity Check Value). The
encrypted message C was therefore determined using the following formula:
C = [ M || ICV(M) ] + [ RC4(K || IV) ]
where || is a concatenation operator and + is a XOR operator

Figure : WEP encryption protocol

23
What’s wrong with WEP?
IV values can be reused
In fact the standard does not specify that the value needs to change at all. Reusing keys is a
major cryptographic weakness in any security system.
IV length is too short
24 bit keys allow for around 16.7 million possibilities. Sounds a lot, but on a busy network
this number can be achieved in a few hours.
Weak keys are susceptible to attack
Certain keys value combinations, ’Weak IVs’, do not produce sufficiently random data for
the first few bytes. This is the basis of the highly publicized attacks on WEP and the reason
that keys can be discovered.
Manufacturers often deliberately disallow Weak IV values. This is good in that it reduces the
chances of a hacker capturing weak keys, but also has the effect of reducing the already
limited key possibilities further, increasing the chance of reuse of keys.
Master keys are used directly
From a cryptographic point of view using master keys directly is not at all recommended.
Master keys should only be used to generate other temporary keys. WEP is seriously flawed
in this respect.
Key Management and updating is poorly provided for
Administration of WEP keys is not well designed and difficult to do on large networks. Users
tend to change keys very infrequently which gives a potential hacker lots of time to collect
enough packets to launch an attack.
Message integrity checking is ineffective
WEP does have a message integrity check but hackers can change messages and recompute
a new value to match. This makes the checking ineffective against tampering.
Conclusion
Although WEP is far from an ideal security solution you should still use it. Some security is
better than none. A determined attacker may be able to discover your keys given time and
enough weak IVs, but that’s no reason to leave all of your doors open.

24
WPA (Wifi Protected access)
Wi-Fi Protected Access, or WPA, was introduced to correct the inherent weaknesses
of WEP. Although it does improve security, it has its own problems. The encryption key used
by WPA relies on a passphrase, the service set identification name (SSID), SSID length and a
random value. The majority of the information used to create this 256-bit key is readily
known, so a would-be hacker needs only guess the passphrase to have access to the
network. Dictionary attacks systematically attempt numerous combinations of words,
characters and phrases to guess this passphrase. It was determined that a passphrase
comprised of less than 20 characters could be defeated.
TKIP packet is comprised of three parts:


1. A 128-bit temporal key that is shared by both clients and access points.



2. An MAC address of a client device.



3. A 48-bit initialization vector describes a packet sequence number.

TKIP packet


This combination guarantees various wireless clients use different keys.



In order to be compatible with existing hardware, TKIP uses the same encryption
algorithm (RC4) as WEP. As such, only software or firmware upgrade is required to
implement TKIP. Compared with WEP, TKIP changes the temporal keys every10000
packets. This dynamic distribution leaves potential hackers little room to crack TKIP
key.



In general, most security experts believe that TKIP is a stronger encryption than
WEP. However, they also agree that TKIP should be an interim solution because of its
use of RC4 algorithm.

A summary of WPA benefits


In general, the security advantages of WPA over WEP are:



Apply stronger network access control through mutual authentication



Support better security technologies like 802.1X, EAP, RADIUS and preshared keys



Adopt dynamic keys in TKIP to establish better key management



Enforce data integrity through Michael Message Integrity Check



Provide forward compatibility to ultimate wireless security solution, 802.11i

25
WPA potential security issues:


There are still potential encryption weaknesses in TKIP. Fortunately, the successful
crack is expected to be heavy and expensive.



Performance may be sacrificed potentially due to a more complex and computation
intensive authentication and encryption protocols.

WPA2 Wi-Fi Protected Access 2


Was ratified in 2004 as a solution to the key encryption problems contained in WEP
and WPA.



A couple of small flaws appeared in WPA2, which require a quality of service attack
or physical positioning between the user and router, but neither of these flaws are
considered a severe threat that exposes user data.



WPA2 offers two encryption algorithms: AES and TKIP. TKIP is essentially WPA
encryption, so for the benefits of WPA2 encryption, you should choose AES.



Another option on most routers is to choose both, which allows the stronger
security of AES when applicable, but uses the weaker TKIP when compatibility issues
arise.

WIFI Security Tips

Wireless networking can be kind of scary from a security standpoint. It opens up whole new
attack vectors that were not present with wired network infrastructures. That doesn't mean
you can't do it securely, however, and I aim to give you some ideas that can help you in that
regard.


Don't broadcast your SSID. -



Use good wireless encryption. -WEP is not exactly "good" encryption. With a freely
available tool like aircrack, you can sniff wireless traffic protected by WEP and crack
security on that network in a matter of minutes. WPA is the current, common
encryption standard you should probably be using -- though, of course, you should
use something stronger as soon as it becomes available to you. Technology is
advancing every day, on both sides of the encryption arms race, after all.

26


Restrict access by MAC address. -restricting the MAC addresses allowed to connect
to the network helps ensure you are not one of the "low hanging fruits" that people
prefer to attack.



Shut down the network when it's not being used-If you have the sort of network
that does not need to be running twenty-four hours a day, seven days a week, you
can reduce the availability of it to security crackers by turning it off when it isn't in
use.



Monitor your network for intruders. You should always make sure you have an eye
on what's going on, that you are tracking attack trends. The more you know about
what malicious security crackers are trying to do to your network, the better the job
of defending against them you can do. Collect logs on scans and access attempts, use
any of the hundreds of statistics generating tools that exist to turn those logs into
more useful information, and set up your logging server to email you when
something really anomalous happens.



Cover the bases. Make sure you have some kind of good firewall running, whether
on a wireless router or on a laptop you use to connect to wireless networks away
from home

Is Wi-Fi Safe for Human?
Wifi health effects on the human body are commonly dismissed because we love the
convenience. Wi-Fi dangers are ignored. After all we can walk around our house with our
laptop and not lose connection. No messy inconvenient cords. We can keep up with mails
and conduct our work at coffee shops, airports, hotels, even hospitals. Who wants to give
up ths kind of convenience?
And yet, have we stopped to think about the fact that there was no safety testing conducted
before it went into used.
Here are some of the most common symptoms people report when exposed to microwave
radiation from cell phones and towers


Chronic headaches



Memory Problems



Dizziness



Depression, Anxiety
27


Sleep Disturbances



Tremors

CONCLUSION
Wireless security has undergone major evolutions in last 7 years. WEP, the original
security standard, is widely considered as broken. The IEEE 802.11 Group, the Wi-Fi
Alliance and major network equipment vendors like Cisco are all working together to
develop a new level of security standards.

28
References
SANS Institute InfoSec Reading Room
www.sans.org/reading-room/whitepapers/wireless/evolutionwireless-security-80211-networks-wep-wpa-80211-standards1109
802.11ac: The Fifth Generation of Wi-Fi Technical White Paper
http://www.cisco.com/en/US/prod/collateral/wireless/
ps5678/ps11983/white_paper_c11713103_ns767_Networking_Solutions White_Paper.html

29

More Related Content

What's hot

Wi-Fi technology presentation
Wi-Fi technology presentationWi-Fi technology presentation
Wi-Fi technology presentation
Eyad Manna
 
Wi fi technology ppt mine
Wi fi technology ppt mineWi fi technology ppt mine
Wi fi technology ppt mine
Roshni Ayappan
 
Li fi(led transmission of data) presentation
Li fi(led transmission of data) presentationLi fi(led transmission of data) presentation
Li fi(led transmission of data) presentation
Kakashi57
 

What's hot (20)

Wi-fi (ppt) by Mayank Saxena
Wi-fi (ppt) by Mayank SaxenaWi-fi (ppt) by Mayank Saxena
Wi-fi (ppt) by Mayank Saxena
 
Presentation on Gi-Fi
Presentation on Gi-FiPresentation on Gi-Fi
Presentation on Gi-Fi
 
Wi-Fi technology presentation
Wi-Fi technology presentationWi-Fi technology presentation
Wi-Fi technology presentation
 
Li fi technology seminar-2014
Li fi technology seminar-2014Li fi technology seminar-2014
Li fi technology seminar-2014
 
Wi fi technology ppt mine
Wi fi technology ppt mineWi fi technology ppt mine
Wi fi technology ppt mine
 
wi-fi technology
 wi-fi technology wi-fi technology
wi-fi technology
 
Li fi ppt
Li fi pptLi fi ppt
Li fi ppt
 
GiFi
GiFi GiFi
GiFi
 
802.11ac
802.11ac802.11ac
802.11ac
 
Wi fi
Wi fiWi fi
Wi fi
 
Basic Concepts in Wireless LAN
Basic Concepts in Wireless LANBasic Concepts in Wireless LAN
Basic Concepts in Wireless LAN
 
Wi-Fi Technology
Wi-Fi TechnologyWi-Fi Technology
Wi-Fi Technology
 
Wireless Networking
Wireless NetworkingWireless Networking
Wireless Networking
 
Wireless Fidelity
Wireless FidelityWireless Fidelity
Wireless Fidelity
 
Li fi(led transmission of data) presentation
Li fi(led transmission of data) presentationLi fi(led transmission of data) presentation
Li fi(led transmission of data) presentation
 
pureLiFi
pureLiFi pureLiFi
pureLiFi
 
Gi-Fi ppt presentation
Gi-Fi ppt presentationGi-Fi ppt presentation
Gi-Fi ppt presentation
 
Wifi ppt
Wifi pptWifi ppt
Wifi ppt
 
Wireless repeaters
Wireless repeatersWireless repeaters
Wireless repeaters
 
LI-FI TECHNOLOGY
LI-FI TECHNOLOGYLI-FI TECHNOLOGY
LI-FI TECHNOLOGY
 

Viewers also liked (9)

Iuwne10 S04 L05
Iuwne10 S04 L05Iuwne10 S04 L05
Iuwne10 S04 L05
 
Wpa vs Wpa2
Wpa vs Wpa2Wpa vs Wpa2
Wpa vs Wpa2
 
Wifi direct technology a technical report
Wifi direct technology   a technical reportWifi direct technology   a technical report
Wifi direct technology a technical report
 
WIFI TECHNOLOGY
WIFI TECHNOLOGYWIFI TECHNOLOGY
WIFI TECHNOLOGY
 
Wireless Security null seminar
Wireless Security null seminarWireless Security null seminar
Wireless Security null seminar
 
Seminar report on Fifth Generation of Wireless Technologies
Seminar report on Fifth Generation of Wireless TechnologiesSeminar report on Fifth Generation of Wireless Technologies
Seminar report on Fifth Generation of Wireless Technologies
 
wi-fi ppt
wi-fi pptwi-fi ppt
wi-fi ppt
 
Wireless security presentation
Wireless security presentationWireless security presentation
Wireless security presentation
 
Slideshare ppt
Slideshare pptSlideshare ppt
Slideshare ppt
 

Similar to WiFi technology Writeup

W I R E L E S S F I D E L I T Y
W I R E L E S S  F I D E L I T YW I R E L E S S  F I D E L I T Y
W I R E L E S S F I D E L I T Y
gou145
 

Similar to WiFi technology Writeup (20)

Wi fi network
Wi fi networkWi fi network
Wi fi network
 
Wifi
WifiWifi
Wifi
 
WiFi part II
WiFi part IIWiFi part II
WiFi part II
 
Wifi
WifiWifi
Wifi
 
wifi himanshu
wifi himanshuwifi himanshu
wifi himanshu
 
Wi Fi Technology
Wi Fi TechnologyWi Fi Technology
Wi Fi Technology
 
-Communication Engineering.pptx
-Communication Engineering.pptx-Communication Engineering.pptx
-Communication Engineering.pptx
 
Wi-Fi
Wi-FiWi-Fi
Wi-Fi
 
Wi fi Technology
Wi fi TechnologyWi fi Technology
Wi fi Technology
 
Wireless Fidelity (WiFi)
Wireless Fidelity (WiFi)Wireless Fidelity (WiFi)
Wireless Fidelity (WiFi)
 
W I R E L E S S F I D E L I T Y
W I R E L E S S  F I D E L I T YW I R E L E S S  F I D E L I T Y
W I R E L E S S F I D E L I T Y
 
Wi Fi
Wi FiWi Fi
Wi Fi
 
WiFi Technology & IEEE
WiFi Technology & IEEEWiFi Technology & IEEE
WiFi Technology & IEEE
 
Presentation over Wi-Fi technology
Presentation over Wi-Fi technologyPresentation over Wi-Fi technology
Presentation over Wi-Fi technology
 
wireless networks.pptx
wireless networks.pptxwireless networks.pptx
wireless networks.pptx
 
Wi fi
Wi fiWi fi
Wi fi
 
A Review on Wireless Technologies
A Review on Wireless TechnologiesA Review on Wireless Technologies
A Review on Wireless Technologies
 
Wi fi technology
Wi fi technologyWi fi technology
Wi fi technology
 
Wi-Fi Architecture
Wi-Fi ArchitectureWi-Fi Architecture
Wi-Fi Architecture
 
Wi fi technology
Wi fi technologyWi fi technology
Wi fi technology
 

More from Shital Kat (8)

Opinion Mining
Opinion MiningOpinion Mining
Opinion Mining
 
Introduction to HADOOP
Introduction to HADOOPIntroduction to HADOOP
Introduction to HADOOP
 
Big data processing using - Hadoop Technology
Big data processing using - Hadoop TechnologyBig data processing using - Hadoop Technology
Big data processing using - Hadoop Technology
 
Query By humming - Music retrieval technology
Query By humming - Music retrieval technologyQuery By humming - Music retrieval technology
Query By humming - Music retrieval technology
 
Query By Humming - Music Retrieval Technique
Query By Humming - Music Retrieval TechniqueQuery By Humming - Music Retrieval Technique
Query By Humming - Music Retrieval Technique
 
School admission process management system (Documention)
School admission process management system (Documention)School admission process management system (Documention)
School admission process management system (Documention)
 
Wifi Security
Wifi SecurityWifi Security
Wifi Security
 
WIFI Introduction (PART I)
WIFI Introduction (PART I)WIFI Introduction (PART I)
WIFI Introduction (PART I)
 

Recently uploaded

Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo DiehlFuture Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
Peter Udo Diehl
 

Recently uploaded (20)

SOQL 201 for Admins & Developers: Slice & Dice Your Org’s Data With Aggregate...
SOQL 201 for Admins & Developers: Slice & Dice Your Org’s Data With Aggregate...SOQL 201 for Admins & Developers: Slice & Dice Your Org’s Data With Aggregate...
SOQL 201 for Admins & Developers: Slice & Dice Your Org’s Data With Aggregate...
 
Syngulon - Selection technology May 2024.pdf
Syngulon - Selection technology May 2024.pdfSyngulon - Selection technology May 2024.pdf
Syngulon - Selection technology May 2024.pdf
 
The Value of Certifying Products for FDO _ Paul at FIDO Alliance.pdf
The Value of Certifying Products for FDO _ Paul at FIDO Alliance.pdfThe Value of Certifying Products for FDO _ Paul at FIDO Alliance.pdf
The Value of Certifying Products for FDO _ Paul at FIDO Alliance.pdf
 
Integrating Telephony Systems with Salesforce: Insights and Considerations, B...
Integrating Telephony Systems with Salesforce: Insights and Considerations, B...Integrating Telephony Systems with Salesforce: Insights and Considerations, B...
Integrating Telephony Systems with Salesforce: Insights and Considerations, B...
 
Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo DiehlFuture Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
Future Visions: Predictions to Guide and Time Tech Innovation, Peter Udo Diehl
 
Simplified FDO Manufacturing Flow with TPMs _ Liam at Infineon.pdf
Simplified FDO Manufacturing Flow with TPMs _ Liam at Infineon.pdfSimplified FDO Manufacturing Flow with TPMs _ Liam at Infineon.pdf
Simplified FDO Manufacturing Flow with TPMs _ Liam at Infineon.pdf
 
Behind the Scenes From the Manager's Chair: Decoding the Secrets of Successfu...
Behind the Scenes From the Manager's Chair: Decoding the Secrets of Successfu...Behind the Scenes From the Manager's Chair: Decoding the Secrets of Successfu...
Behind the Scenes From the Manager's Chair: Decoding the Secrets of Successfu...
 
AI revolution and Salesforce, Jiří Karpíšek
AI revolution and Salesforce, Jiří KarpíšekAI revolution and Salesforce, Jiří Karpíšek
AI revolution and Salesforce, Jiří Karpíšek
 
Choosing the Right FDO Deployment Model for Your Application _ Geoffrey at In...
Choosing the Right FDO Deployment Model for Your Application _ Geoffrey at In...Choosing the Right FDO Deployment Model for Your Application _ Geoffrey at In...
Choosing the Right FDO Deployment Model for Your Application _ Geoffrey at In...
 
Demystifying gRPC in .Net by John Staveley
Demystifying gRPC in .Net by John StaveleyDemystifying gRPC in .Net by John Staveley
Demystifying gRPC in .Net by John Staveley
 
Secure Zero Touch enabled Edge compute with Dell NativeEdge via FDO _ Brad at...
Secure Zero Touch enabled Edge compute with Dell NativeEdge via FDO _ Brad at...Secure Zero Touch enabled Edge compute with Dell NativeEdge via FDO _ Brad at...
Secure Zero Touch enabled Edge compute with Dell NativeEdge via FDO _ Brad at...
 
Buy Epson EcoTank L3210 Colour Printer Online.pdf
Buy Epson EcoTank L3210 Colour Printer Online.pdfBuy Epson EcoTank L3210 Colour Printer Online.pdf
Buy Epson EcoTank L3210 Colour Printer Online.pdf
 
FDO for Camera, Sensor and Networking Device – Commercial Solutions from VinC...
FDO for Camera, Sensor and Networking Device – Commercial Solutions from VinC...FDO for Camera, Sensor and Networking Device – Commercial Solutions from VinC...
FDO for Camera, Sensor and Networking Device – Commercial Solutions from VinC...
 
What's New in Teams Calling, Meetings and Devices April 2024
What's New in Teams Calling, Meetings and Devices April 2024What's New in Teams Calling, Meetings and Devices April 2024
What's New in Teams Calling, Meetings and Devices April 2024
 
Enterprise Knowledge Graphs - Data Summit 2024
Enterprise Knowledge Graphs - Data Summit 2024Enterprise Knowledge Graphs - Data Summit 2024
Enterprise Knowledge Graphs - Data Summit 2024
 
Where to Learn More About FDO _ Richard at FIDO Alliance.pdf
Where to Learn More About FDO _ Richard at FIDO Alliance.pdfWhere to Learn More About FDO _ Richard at FIDO Alliance.pdf
Where to Learn More About FDO _ Richard at FIDO Alliance.pdf
 
Custom Approval Process: A New Perspective, Pavel Hrbacek & Anindya Halder
Custom Approval Process: A New Perspective, Pavel Hrbacek & Anindya HalderCustom Approval Process: A New Perspective, Pavel Hrbacek & Anindya Halder
Custom Approval Process: A New Perspective, Pavel Hrbacek & Anindya Halder
 
Measures in SQL (a talk at SF Distributed Systems meetup, 2024-05-22)
Measures in SQL (a talk at SF Distributed Systems meetup, 2024-05-22)Measures in SQL (a talk at SF Distributed Systems meetup, 2024-05-22)
Measures in SQL (a talk at SF Distributed Systems meetup, 2024-05-22)
 
Speed Wins: From Kafka to APIs in Minutes
Speed Wins: From Kafka to APIs in MinutesSpeed Wins: From Kafka to APIs in Minutes
Speed Wins: From Kafka to APIs in Minutes
 
IESVE for Early Stage Design and Planning
IESVE for Early Stage Design and PlanningIESVE for Early Stage Design and Planning
IESVE for Early Stage Design and Planning
 

WiFi technology Writeup

  • 1. SEMINARS OF SEMISTER – I [ YEAR 2013-2014 ] NAME: SHITAL KATKAR TOPIC: Wifi Technology SIGNATURE:________________ 1
  • 2. SEMINAR – I WIFI Technology 2
  • 3. CONTENTS:  Wifi Technology  Radio waves  Flavors Of Wifi  Applications  Advantages  Limitation  Conclusion 3
  • 4. INTRODUCTION Technology is making rapid progress and is making many things easier.As the innovative thinking of persons is increasing day-by-day,new methods for wireless networking has been evolved of which our present topic Wi-Fi is the most accepted technology. Wi-Fi, an acronym for Wireless-Fidelity which is the wireless way to handle networking. It is also known as 802.11 networking. The big advantage of WiFi is its simplicity. You can connect computers anywhere in your home or office without the need for wires. The computers connect to the network using radio signals, and computers can be up to 100 feet or so apart. RADIO WAVES This is the Electromagnatic spectrum. Range of Radio Wave is 3 kHz to 300 GHz. Radio waves are mainly use for communication. Wifi uses radio technology. 4
  • 5. FLAVOURS OF WIFI IEEE 802.11, is a set of standards to allow different devices to communicate wirelessly. It is created by the IEEE (pronounced eye-triple-e) LAN/MAN Standards Committee. • IEEE 802.11b • IEEE 802.11a • IEEE 802.11g • IEEE 802.11n IEEE 802.11 b  Appear in late 1999  Operates at 2.4GHz radio spectrum  11 Mbps (theoretical speed) - within 30 m Range  4-6 Mbps (actual speed)  100 -150 feet range  Most popular, Least Expensive  Interference from mobile phones and Bluetooth devices which can reduce the transmission speed. IEEE 802.11 a  Introduced in 2001  Operates at 5 GHz (less popular)  54 Mbps (theoretical speed  15-20 Mbps (Actual speed)  50-75 feet range  More expensive  Not compatible with 802.11b 5
  • 6. IEEE 802.11 g  Introduced in 2003  Combine the feature of both standards (a,b)  100-150 feet range  54 Mbps Speed  2.4 GHz radio frequencies  Compatible with ‘b’  Use OFDM Technology (OFDM is a orthogonal frequency division multiplexing. It is basically a method of encoding digital data on multiple carrier frequencies) IEEE 802.11 n  Introduced in 2009  Uses multiple antennas that function in a "MIMO" mode ( multiple-input multipleoutput)  2.5 GHz and 5 GHz radio frequency  150 Mbps speed  Range up to 230 feet indoor 6
  • 7. APPLICATIONS OF WIFI These are the placese where wifi is used o Home o Small Businesses or SOHO o Large Corporations & Campuses o Health Care o Wireless ISP (WISP) o Travelers Many devices can use wi-fi e.g. personal computers, video-game consoles, smartphones, some digital cameras, tablet computers and digital audio players. These can connect to a network resource such as the Internet via a wireless network access point. ADVANTAGES OF WI-FI 1. Wi-Fi is a core technology in GPS Industries Applications. 2. Wi-Fi technology available in hotels, airports, etc., will be more inclined to bring laptop with us when traveling for personal reasons. 3. Frees network devices from cables, allows for a more dynamic network to be grown. 1. Changes the way people live, communicate, work and play. 4. Many reliable and bug-free Wi-Fi products on the market 2. 5.It helps to become more productive at home, like online shopping and banking; 5. Wi-Fi technology allows getting out of home office and working in other rooms. 7
  • 8. DISADVANTAGES OF WI-FI 1. 1.The 802.11b and 802.11g flavors of Wi-Fi use the 2.4 GHz spectrum, which is crowded with other devices such as Bluetooth, microwave ovens, cordless phones, or video sender devices, among many others. 2. 2.Power consumption is fairly high compared to other standards, making battery life and heat a concern. 3. 3.It is not always configured properly by users. CONCLUSION As Wi-Fi is now shipped in millions of products and deployed in millions of homes, business and hotspots worldwide, the technology has moved beyond the realm of a computer feature. Wi-Fi has fast become a cultural phenomenon. 8
  • 9. SEMINAR – II WIFI Technology 9
  • 10. CONTENTS:  Elements of WIFI  Walkie Talkie Network  WIFI's Radio Technology  Working of WIFI  Communication in WIFI  Adding WIFI to a computer  WIFI's network topologies  Conclusion 10
  • 11. Elements of a WI-FI Network  Access Point (AP) - The AP is a wireless LAN transceiver or “base station” that can connect one or many wireless devices simultaneously to the Internet.  Wi-Fi cards - They accept the wireless signal and relay information. They can be internal and external. (e.g PCMCIA Card for Laptop and PCI Card for Desktop PC)  Safeguards - Firewalls and anti-virus software protect networks from uninvited users and keep information secure. Wi-Fi’s Walkie-Talkie Network To understand the wire less technology let us consider a pair of Walkie-Talkies.These are small radios that can transmit and receive radio signals.When we talk into a WalkieTalkie, our voice is picked up by a microphone, encoded onto a radio frequency and transmitted with the antenna. Another Walkie-Talkie can receive the transmission with its antenna, decode our voice from the radio signal and drive a speaker. Simple Walkie-Talkies like this transmit at a signal strength of about 0.25 watts, and they can transmit about 500 to 1,000 feet. If we want to connect two computers together in a network using Walkie-Talkie technology. Equip each computer with a Walkie-Talkie. Give each computer a way to set whether it wants to transmit or receive. Give the computer a way to turn its binary 1s and 0s into two different beeps that the walkie-talkie could transmit and receive and convert back and forth between beeps and 1s/0s. This would actually work. The only problem would be that the data rate would be very slow. Walkie-talkie is designed to handle the human voice.So it is not being able to send very much data in this way(may be 1,000 bits per second). 11
  • 12. Wi-Fi's Radio Technology  WiFi radios that work with the 802.11b and 802.11g standards transmit at 2.4 GHz, while those that work with the 802.11a standard transmit at 5 GHz. Normal walkietalkies normally operate at 49 MHz. The higher frequency allows higher data rates.  WiFi radios use much more efficient coding techniques that also contribute to the much higher data rates. For 802.11a and 802.11g, the technique is known as orthogonal frequency-division multiplexing (OFDM). For 802.11b, it is called Complementary Code Keying (CCK).  The radios used for WiFi have the ability to change frequencies. 802.11b cards can transmit directly on any of three bands, or they can split the available radio bandwidth into dozens of channels and frequency hop rapidly between them. The advantage of frequency hopping is that it is much more immune to interference and can allow dozens of WiFi cards to talk simultaneously without interfering with each other. WORKING OF WIFI The most important items which makes Wi-Fi working in the laptop or desktop are  Radio Signals  Wi-Fi Card which fits in your laptop or computer.  Hotspots which create Wi-Fi Network. 12
  • 13. o A Wi-Fi hotspot is created by installing an access point to an internet connection. o An access point acts as a base station. o When Wi-Fi enabled device encounters a hotspot the device can then connect to that network wirelessly. o A single access point can support up to 30 users and can function within a range of 100 – 150 feet indoors and up to 300 feet outdoors. o Many access points can be connected to each other via Ethernet cables to create a single large network. Radio Signals:  Radio Signals are the keys which make WiFi networking possible. These radio signals transmitted from Wi-Fi antennas are picked up by WiFi receivers such as computers and cell phones that are equipped with WiFi cards. Whenever a computer receives any of the signals within the range of a WiFi network which is usually 300 - 500 feet for antennas, the WiFi card will read the signals and thus create an internet connection between the user and the network without the use of a cord.  Access points which consist of antennas and routers are the main source which transmit and receive radio waves.  Antennas work stronger and have a longer radio transmission with a radius of 300500 feet which are used in public areas while the weaker yet effective router is more suitable for homes with a radio transmission of 100-150 feet. Wi-Fi Cards: You can think WiFi card as being an invisible cord that connects your computer to the antenna for a direct connection to the internet.  WiFi cards can be external or internal, meaning that if a WiFi card is not installed in your computer, you may purchase a USB antenna attachment and have it externally connect to your USB port, or have an antenna-equipped expansion card installed directly to the computer. For laptops, this card will be a PCMCIA card in which you insert to the PCMCIA slot on the laptop. 13
  • 14. Wi-Fi Hotspots  A Wi-Fi hotspot is created by installing an access point to an internet connection. The access point transmits a wireless signal over a short distance . typically covering around 300 feet. When a Wi-Fi enabled device, such as a Pocket PC, encounters a hotspot, the device can then connect to that network wirelessly.  Most hotspots are located in places that are readily accessible to the public, like airports, coffee shops, hotels, book stores and campus environments. 802.11b is the most common specification for hotspots worldwide. The 802.11g standard is backwards compatible with .11b but .11a uses a different frequency range and requires separate hardware such as an a, a/g, or a/b/g adapter. The largest public Wi-Fi networks are provided by private internet service providers (ISPs) that charge a fee for users to connect to the internet. COMMUNICATION IN WI-FI Data exchange in Wi-Fi can be summarized into three phases: Phase I: Where data is prepared for transmission; it is encoded; changed into frames (digital signals are sent in frames for better QoS). The frequency for data transmission is also chosen depending upon the technique used to send the signals wirelessly. Phase II: Where data is transmitted with air as the medium of wave transmission 14
  • 15. Phase III: Where data is received, decoded, acknowledged and then used. All of these phases apply some of the popular digital communications spread spectrum techniques for signal multiplexing (FHSS, Infrared, OFDM etc.), make use of security methods (WEP, WPA). Adding WiFi to a Computer Many new laptops come with a Wi-Fi card built in. It is also easy to add a Wi-Fi card to an older laptop or a desktop PC. The process is  Take a 802.11a, 802.11b or 802.11g network card. 802.11g has the advantage of higher speeds and good interoperability on 802.11b equipment.  For a laptop, this card will normally be a PCMCIA card that slide into a PCMCIA slot on laptop. Or take a small external adapter and plug it into a USB port.  For a desktop machine, take a PCI card & install inside the machine, or a small external adapter and connect to the computer with a USB cable.  Install the card  Install the drivers for the card  Find an 802.11 hotspot  Access the hotspot. 15
  • 16. WI-FI NETWORK TOPOLOGIES 1. AP-based topology (Infrastructure Mode) 2. Peer-to-peer topology (Ad-hoc Mode) 3. Point-to-multipoint bridge topology AP-based topology (Infrastructure mode)  The client communicate through Access Point.  BSA-RF coverage provided by an AP.  ESA-It consists of 2 or more BSA.  ESA cell includes 10-15% overlap to allow roaming. Peer-to-peer TOPOLOGY  AP is not required.  Client devices within a cell can communicate directly with each other.  It is useful for setting up of a wireless network quickly and easily. 16
  • 17. Point-to-multipoint bridge TOPOLOGY  This is used to connect a LAN in one building to a LANs in other buildings even if the buildings are miles apart. These conditions receive a clear line of sight between buildings. The line-of-sight range varies based on the type of wireless bridge and antenna used as well as the environmental conditions. Conclusion  Wi-fi is a simple, cost-effective way to connect to the Internet , Without the need to physically connecting wires.  Hotspot s a geographic area setup in any public location, and has a readily accessible wireless network  Security is a huge challenge for Wi-Fi Networks, many Security Techniques are used to improve it. The Future of Wi-Fi This is the graph of Hotels offering Wi-Fi. The future of Wi-Fi is very bright. Its growing in popularity because of decreasing cost and the freedom it gives to users. 17
  • 18. SEMINAR – III WIFI Security 18
  • 19. CONTENTS:  Need of security  Wi-Fi Security Threats  Security requirements  Security Techniques  Wi-Fi security tips  Conclusion 19
  • 20. Security is essential part of Wifi Technology. Wi-Fi can be less secure than wired connections (such as Ethernet) because an intruder does not need a physical connection. Why security is more of a concern in wireless?  no inherent physical protection  physical connections between devices are replaced by logical associations  sending and receiving messages do not need physical access to the network infrastructure (cables, hubs, routers, etc.  ƒ broadcast communications  wireless usually means radio, which has a broadcast nature  transmissions can be overheard by anyone in range – anyone can generate transmissions,  • which will be received by other devices in range  • which will interfere with other nearby transmissions and may prevent their correct reception (jamming). Wi-Fi Security Threats Wireless technology doesn’t remove any old security issue, but introduces new ones o Eavesdropping o Man-in-the-middle attacks o Denial of Service 20
  • 21. Eavesdropping Eavesdropping is the act of secretly listening to the private conversation of others without their consent.  Easy to perform, most impossible to detect  By default , everything is transmitted in clear text   -No secuirty offered by the transmission medium  Different tools available on the internet  -Network sniffers, protocol analysers   -Username, passwds,content... -Passwd collectors With the right equipment, it’s possible to eavesdrop traffic from few kilometres away Man In The Middle Attack An attack where a user gets between the sender and receiver of information and sniffs any information being sent.  Attacker spoofs a disassociate message from the victim  The victim starts to look for a new access point, and the attacker advertises his own AP on a different channel, using he real Aps MAC address  The attacker connects to the real  AP using victim’s MAC address 21
  • 22. Denial of Service Denial-of-service attack (DoS attack) is an attempt to make a machine or network resource unavailable to its intended users.  Attack on transmission regency used    Frequency jamming Not very technical, but works Attack on MAC layer    Spoofed deauthentication / disassociatin messages Can target on specific user Attacks on higher layer protocol(TCP/IP protocol)  SYN Flooding Wireless communication security requirements  Confidentiality – messages sent must be encrypted  Authenticity – origin of messages received must be verified  Replay detection – freshness of messages received must be checked  Integrity – modifying messages on-the-fly (during radio transmission) is not so easy, but possible, Integrity of messages received must be verified  ƒ Access control – access to the network services should be provided only to legitimate entities SECURITY TECHNIQUES  Open/free/Unsecured (No Password)  WEP (Wired Equivalent privacy)  WPA (Wifi Protected access)  WPA II 22
  • 23. Unsecured/Open Leaving your Wi-Fi unsecured is synonymous with leaving your front door wide open, so anyone could simply walk in. Leaving your Wi-Fi unsecured also transmits data packets between users and the router in unencrypted format, which makes these data packets easy to intercept and read. WEP (Wired Equivalent Privacy) WEP (Wired Equivalent Privacy) was the default encryption protocol introduced in the first IEEE 802.11 standard back in 1999. It is based on the RC4 encryption algorithm, with a secret key of 40 bits or 104 bits being combined with a 24-bit Initialisation Vector (IV) to encrypt the plaintext message M and its checksum – the ICV (Integrity Check Value). The encrypted message C was therefore determined using the following formula: C = [ M || ICV(M) ] + [ RC4(K || IV) ] where || is a concatenation operator and + is a XOR operator Figure : WEP encryption protocol 23
  • 24. What’s wrong with WEP? IV values can be reused In fact the standard does not specify that the value needs to change at all. Reusing keys is a major cryptographic weakness in any security system. IV length is too short 24 bit keys allow for around 16.7 million possibilities. Sounds a lot, but on a busy network this number can be achieved in a few hours. Weak keys are susceptible to attack Certain keys value combinations, ’Weak IVs’, do not produce sufficiently random data for the first few bytes. This is the basis of the highly publicized attacks on WEP and the reason that keys can be discovered. Manufacturers often deliberately disallow Weak IV values. This is good in that it reduces the chances of a hacker capturing weak keys, but also has the effect of reducing the already limited key possibilities further, increasing the chance of reuse of keys. Master keys are used directly From a cryptographic point of view using master keys directly is not at all recommended. Master keys should only be used to generate other temporary keys. WEP is seriously flawed in this respect. Key Management and updating is poorly provided for Administration of WEP keys is not well designed and difficult to do on large networks. Users tend to change keys very infrequently which gives a potential hacker lots of time to collect enough packets to launch an attack. Message integrity checking is ineffective WEP does have a message integrity check but hackers can change messages and recompute a new value to match. This makes the checking ineffective against tampering. Conclusion Although WEP is far from an ideal security solution you should still use it. Some security is better than none. A determined attacker may be able to discover your keys given time and enough weak IVs, but that’s no reason to leave all of your doors open. 24
  • 25. WPA (Wifi Protected access) Wi-Fi Protected Access, or WPA, was introduced to correct the inherent weaknesses of WEP. Although it does improve security, it has its own problems. The encryption key used by WPA relies on a passphrase, the service set identification name (SSID), SSID length and a random value. The majority of the information used to create this 256-bit key is readily known, so a would-be hacker needs only guess the passphrase to have access to the network. Dictionary attacks systematically attempt numerous combinations of words, characters and phrases to guess this passphrase. It was determined that a passphrase comprised of less than 20 characters could be defeated. TKIP packet is comprised of three parts:  1. A 128-bit temporal key that is shared by both clients and access points.  2. An MAC address of a client device.  3. A 48-bit initialization vector describes a packet sequence number. TKIP packet  This combination guarantees various wireless clients use different keys.  In order to be compatible with existing hardware, TKIP uses the same encryption algorithm (RC4) as WEP. As such, only software or firmware upgrade is required to implement TKIP. Compared with WEP, TKIP changes the temporal keys every10000 packets. This dynamic distribution leaves potential hackers little room to crack TKIP key.  In general, most security experts believe that TKIP is a stronger encryption than WEP. However, they also agree that TKIP should be an interim solution because of its use of RC4 algorithm. A summary of WPA benefits  In general, the security advantages of WPA over WEP are:  Apply stronger network access control through mutual authentication  Support better security technologies like 802.1X, EAP, RADIUS and preshared keys  Adopt dynamic keys in TKIP to establish better key management  Enforce data integrity through Michael Message Integrity Check  Provide forward compatibility to ultimate wireless security solution, 802.11i 25
  • 26. WPA potential security issues:  There are still potential encryption weaknesses in TKIP. Fortunately, the successful crack is expected to be heavy and expensive.  Performance may be sacrificed potentially due to a more complex and computation intensive authentication and encryption protocols. WPA2 Wi-Fi Protected Access 2  Was ratified in 2004 as a solution to the key encryption problems contained in WEP and WPA.  A couple of small flaws appeared in WPA2, which require a quality of service attack or physical positioning between the user and router, but neither of these flaws are considered a severe threat that exposes user data.  WPA2 offers two encryption algorithms: AES and TKIP. TKIP is essentially WPA encryption, so for the benefits of WPA2 encryption, you should choose AES.  Another option on most routers is to choose both, which allows the stronger security of AES when applicable, but uses the weaker TKIP when compatibility issues arise. WIFI Security Tips Wireless networking can be kind of scary from a security standpoint. It opens up whole new attack vectors that were not present with wired network infrastructures. That doesn't mean you can't do it securely, however, and I aim to give you some ideas that can help you in that regard.  Don't broadcast your SSID. -  Use good wireless encryption. -WEP is not exactly "good" encryption. With a freely available tool like aircrack, you can sniff wireless traffic protected by WEP and crack security on that network in a matter of minutes. WPA is the current, common encryption standard you should probably be using -- though, of course, you should use something stronger as soon as it becomes available to you. Technology is advancing every day, on both sides of the encryption arms race, after all. 26
  • 27.  Restrict access by MAC address. -restricting the MAC addresses allowed to connect to the network helps ensure you are not one of the "low hanging fruits" that people prefer to attack.  Shut down the network when it's not being used-If you have the sort of network that does not need to be running twenty-four hours a day, seven days a week, you can reduce the availability of it to security crackers by turning it off when it isn't in use.  Monitor your network for intruders. You should always make sure you have an eye on what's going on, that you are tracking attack trends. The more you know about what malicious security crackers are trying to do to your network, the better the job of defending against them you can do. Collect logs on scans and access attempts, use any of the hundreds of statistics generating tools that exist to turn those logs into more useful information, and set up your logging server to email you when something really anomalous happens.  Cover the bases. Make sure you have some kind of good firewall running, whether on a wireless router or on a laptop you use to connect to wireless networks away from home Is Wi-Fi Safe for Human? Wifi health effects on the human body are commonly dismissed because we love the convenience. Wi-Fi dangers are ignored. After all we can walk around our house with our laptop and not lose connection. No messy inconvenient cords. We can keep up with mails and conduct our work at coffee shops, airports, hotels, even hospitals. Who wants to give up ths kind of convenience? And yet, have we stopped to think about the fact that there was no safety testing conducted before it went into used. Here are some of the most common symptoms people report when exposed to microwave radiation from cell phones and towers  Chronic headaches  Memory Problems  Dizziness  Depression, Anxiety 27
  • 28.  Sleep Disturbances  Tremors CONCLUSION Wireless security has undergone major evolutions in last 7 years. WEP, the original security standard, is widely considered as broken. The IEEE 802.11 Group, the Wi-Fi Alliance and major network equipment vendors like Cisco are all working together to develop a new level of security standards. 28
  • 29. References SANS Institute InfoSec Reading Room www.sans.org/reading-room/whitepapers/wireless/evolutionwireless-security-80211-networks-wep-wpa-80211-standards1109 802.11ac: The Fifth Generation of Wi-Fi Technical White Paper http://www.cisco.com/en/US/prod/collateral/wireless/ ps5678/ps11983/white_paper_c11713103_ns767_Networking_Solutions White_Paper.html 29