Challenges To Wireless And Mobile Networks Computer Science Essay

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Wireless technology can be explained as the means of communication between two or more devices without any physical contact or which basically doesn't require any type of cabling.

Wireless technology is modern technologies which uses radio frequency transmission where as other means of communication is through wired technology in which data exchange is carried out through cabling. Hence, benefits of wireless network s are convenience, mobility, productivity, expandability and cost.

802.11 is a specification for wireless local area networks (WLANs) developed by the Institute of Electrical and Electronics Engineers (IEEE).

Wireless Network is classified into basically 3 groups on the basis of their frequency capturing different coverage:

Wireless Wide Area Network.

Wireless Local Area Network

Lastly, Wireless Personal Area Network.

Wireless Wide Area Network

It different from LAN covering relatively large geographical area and it uses technologies such as mobile telecommunication cellular network e.g WIMAX, GSM, CDMA, GPRS, and 3G for the purpose of the transmission of data. It provides a better option to a user to get connected to internet and other services from laptops through WWAN connectivity.

However, it is not regarded as the safest way of communication due to lack of GSM encryption techniques.

Wireless Local Area Network

It provides a greater flexibility to users as it requires getting devices connected through access point. The maximum range can differ from 70 meters to 100 meters from Access Point. The IEEE 802.11 group of standard states that WLAN 802.11 standard uses Ethernet protocol and carrier sense multiple access with collision avoidance for sharing their path along Wired Equivalent Privacy Algorithm for the purpose of encryption.

Wireless Personal Area Network

It is a wireless connection configuration in personal area network connecting many devices in individual workplace. The distance covered in this type of technology is very small as compared to WLAN ie. only 10 meter. Examples of this are Bluetooth and IF.

Ad-Hoc Network

This type of network doesn't depend on preexisting infrastructure like access point or router. Due to their dynamic network topology these are called Ad-Hoc Network.

In this connection each nodes sends data to other nodes presents in the connection and hence dynamically the selection of nodes is done depending on the network connectivity.

Different types of Wireless Ad-Hoc Networks are:

Mobile Ad-Hoc Network(MANET).

Wireless Mesh Network(WMN).

Wireless Sensor Network(WSN).

With the advancement of Wireless network it has proved to be of very beneficial in many ways like improvement in productivity, increased in accessibility to database of information.

It has also allowed the configuration of network to simple, faster and low in cost. But, with this it has generated a new set of challenges. As the mode of communication is via air using Radio Frequencies hence the risk of information getting intercepted has also increased.

Requirements from a secure mode of communication through network are:


To preserve the confidentiality of the information between sender and receiver only eliminating the possibility of getting information hacked in between.


No other person than sender and receiver should be able to modify the information which is being exchanged.

Authentication :

The receiver capability to identify the source of the message and to make sure that an intruder may not be able to masquerade as someone else.

Service Reliability:

To protect the communication against any threat of Denial of Service(Dos)


Receipt of message verified with the sender.

Unlike in wired communication in this if the message is not encrypted then the attacker can easily hack into the way and can steal confidential information.

Now, wireless & mobile network along with their advantages provides some negative feedback ranging from their vulnerability to the limitation of their technology. Some of the drawbacks of these type of Networks are listed below.

1. Security

2. Range.

3. Reliability

4. Lastly, speed.

Some of the attacks against Wireless Local Area Network/Cellular Network:

Passive Attack: In this type of attack the unauthorized person gets access to the information but he does not modify it. Passive attack can be Eavesdropping or Traffic analysis.

Eavesdropping - In this the attacker captures the packets from the network transmitted by the connected computers and the attacker then try to steal the sensitive information from the data.

Traffic Analysis: - In this mechanism, the attacker gain intelligence by monitoring the transmission for patterns of communication. During flow of messages between two communicating parties considerable amount of information can be extracted.

Active Attacks:

In this type of attack the attacker modifies the information and can even stop the transmission of the data. It is also possible that the unauthorized party can be present between the two communicating parties. Types of active attacks are

Masquerading: In this the attacker pretends to be the authorized and gain unauthorized privileges.

Replay: In this the attacker monitors the transmission of data and maliciously repeats or delays the data later as an authorized user.

Message Modification: The attacker fraudulently modifies the original information by deleting, adding and changing it.

Denial-of -Service: Here, attacker prevents the normal mode of communication and make resources unavailable to users eg. Preventing internet site or service from operating temporarily.

Wireless Network Attack

Accidental Association:

In this a user turns on a computer and then computer get connected to the available wireless access point from a neighboring company's network. In the proprietary company information is exposed and now there could be links between two companies.

Malicious Association:

In this the attacker tries to connect to the company network through the means of cracking laptop instead of company's access point. Such types of laptop used for cracking are known as Soft APs where they on application execution looks like legitimate access point.

Identity Theft(MAC Spoofing)

MAC spoofing is a technique in which the attacker is able to get all network traffic and identify the MAC address of a computer with network privileges. Many wireless network provides access on MAC IDs and hence duplicating the MAC IDs can easily allows the attacker to gain access.

Man in the Middle Attack

This attack intercepts the communication between two systems. This is active form of eavesdropping in which the attacker makes the connection with the victim as the other private connection and thus controlling the overall conversation.

In this the attacker acquires the machine in the communication path of the traffic.

Then, attacker listen all the communication and modify traffic as it is being transmitted through the machine he controls.

Network Injection

Attacker exploits the access points which are made available to the non filtered network traffic for example broadcasting network traffic known as spanning tree, routing information protocol.

Attacker can enter a fake networking re-configuration command that affects the operation of routers, hub switches etc, due to which the whole network can be brought down.

Session Hijacking

In this the attacker exploits the computer session to gain access to the information to the services provided by the computer system. The HTTP sessions cookies which are designed to maintain the session with the sites are compromised to gain access by the attacker as the legitimate user.

Some of the other vulnerabilities and threats which are applicable to Mobile/Wireless network are:

All vulnerabilities which are prone to wired network are applicable in wireless network as well.

Malicious entities can compromise wireless connection by by-passing firewall protection.

Unencrypted data can be intercepted via transmission.

Improper synchronization can lead to corruption of data.

Handheld devices on lost can leak data to unauthorized user.

Improper configuration can also lead to leakage of data.

Virus & other malicious codes con corrupt the data on a wireless device.

Internal attacks are also possible via ad-hoc transmission.

Part -B

The IEEE 802.11 specification provides several services to provide secure operating environment. WEP known as Wired Equivalent Privacy protocol is used to protect link level data during wireless transmission between clients and access points.

WEP uses the stream cipher RC4 for confidentiality and CRC-32 checksum for integrity.

The methods which can be used with WEP for authentication are as follows:

In open system authentication, the mobile station is verified by the access point without verifying the identity of the station hence only mobile station is authenticated not the access point.

Shared key authentication is a cryptographic technique for authentication purpose. Here client sends the authentication request to the access point and acces points responds by sending the challenge text. On receiving the challenge text client encrypts the challenge text and send back to AP. Access point then decrypts the challenge text and if its correct then it authenticates the client, hence client connects to the network.

Security issues surrounding WEP are:

Static WEP keys usage: Sharing of same key for longer duration in wireless network posses a great risk of data leakage. If, any computer is compromised or stolen then the key used can be obtained and the traffic could be brought under analytic attack.

IV in WEP: 24 bits provides 16,777,216 different RC4 cipher streams which are sent in clear portion text of a message. Due to short in length these are repeated very shortly and as a result an attacker can capture the network traffic and can decrypt the cipher text on after retrieval of key stream.

The Integrity Check Value algorithm is not appropriate.

And, Authentication Messages can be easily forged in shared key authentication mechanism as the attacker can observe both the challenge and response and can detect RC4 stream to encrypt the challenge.

Fixation of WEP issue is WPA & WPA2 with the introduction of Temporal Key Integrity Protocol (TKIP). It replaces the WEP 40bit encryption with 128 bit per packet key avoiding collisions.

WPA(Wi-Fi Protected Access) improves the encryption and authentication of feature of Wired equivalent Privacy. It has implemented mainly all the standards of the IEEE 802.11i .

WPA has also acquired a Message Integrity Check which is used to prevent an hacker from modifying or copying data. This feature has replaced cyclic redundancy check that was used by earlier WEP standard. MIC has solved these problems as CRC did not provide any strong data integrity for the packets. However, MIC uses an algorithm to verify the integrity of the packets and then on unsuccessfully verification it drops the packets.

WPA is succeeded by WPA2, it provides security methods to WPA for wireless network and provides strong data protection and network access control. WPA2 is of two different version called WPA2-Personal and WPA2-Enterprise. WPA2 personal utilizes setup password to protect against unauthorized network access and WPA2 enterprise verifies network users via a server.

Eavesdropping attack

In this the attacker captures the packets from the network transmitted by the connected computers and the attacker then try to steal the sensitive information from the data. In this the integrity of the message remains the same but the confidentiality of the message is compromised.

In this communication the two users i.e. Alice and Bob are the legitimate uses communication with each other in wireless network. And, Eve is the unauthorized user who has gained access to the communication. Here, all the information shared between Alice and Bob are being compromised by the attacker Eve who is capturing all the data exchanged between other two legitimate users. Here the integrity of the message is saved but the confidentiality is compromised.

Some types of applications and protocols are vulnerable to eavesdropping attacks are HTTP, FTP, POP, TFTP, Simple Management Network Protocol.

Eavesdropping Tools

Eavesdropping can be increased with the use of hardware and software as well.

Protocol analyzer is used for examining the packets and the analyzer can be hardware type with software compatibility.

Types of protocol analyzer:

General type of protocol analyzer is used to captures all packets and is basically used as a diagnostic tool in order to rectify troubleshoot problems.

Attack type is advancement of general protocol analyzer capturing certain types of applications & protocols for authentication, financial, and security information. An intruder can capitalize this information in order to attack the network with different ways.

Risk Mitigation for Wireless/Mobile Network.

Physical security is the most important consideration is securing the communication by allowing only authorized users to access wireless network. In physical security certain parameters are considered such as access control, personnel identification and external boundary.

Hardware and software solutions shall be used to enhance the security of the wireless/mobile network.

Software measure such as: 1. Proper Access Point configuration.

2. Software patches and upgrades.

3. Authentication.

4. Encryption.

Hardware measure such as: 1. Virtual Private Network

2. Public Key Infrastructure.

3.  Wireless intrusion prevention systems.

Usage of Firewall, Antivirus & Anti-spyware program.

Service Set Identifier (SSID) of Access Point should be changed from its default value.

Identifier broadcasting should be disabled as this can be exploited by the hacker to gain acces to the network.

Default router administrator password shall be changed as most vendors' uses the same password for their products which may be available to attacker and thus attacker can exploit this vulnerability.

Assigning access based on MAC address can be done to minimize the risk of network compromise however an attacker may duplicate the MAC.

Establishment of Access list comprising of all the legitimate users and its periodic verification.