By Malik Asad
Requirements of wireless network
It is the requirement of wireless networks that authentication, confidentiality, integrity, and availability processes must operate properly. which can be defined as
Authentication is the process of confirming whether the person is a legitimate user or not.
It is the process of keeping important information hidden from an unauthorized person like a secret.
Suppose, You are a manager of a company, and you want to keep some important facts and figure hidden from other employees of the company. You are allowed to share important information related to management only with the boss. So you have to do the same.
It means an unauthorized person cannot modify your document.
This process keeps away the hacker from changing the information. For example, you have to attend an important business meeting in another city, and you have booked a flight and received a ticket number. If a hacker changes the integrity of this information, your flight can be canceled.
Availability means that resources must be available for your use whenever you access them.
In networking, availability is an important factor. To ensure the availability of resources, several countermeasures are made because it is necessary for the smooth running of the process. Load balancing is a mechanism that ensures the availability of resources.
OSI layers main specification and protocol
Specification and protocol: HTTP, FTP, and SMTP
Specification and protocol: TCP and UDP
Specification and protocol: IP and ICMP
Specification and protocol: CSMA/CA, ALOHA, CDMA and OFDMA
Specification and protocol: Transmission Medium, Coding, and Modulation
On these layers, different types of attacks occur. In each layer, several possible attacks are given below
On the physical layer, two types of attacks are possible
Type of attack that results in the interception of confidential information.
Interruption of legitimate transmission
Attacks on the MAC layer are
It results in the falsification of the MAC address
Stealing of a legitimate user MAC identity.
Impersonation of a pair of communicating nodes.
It is the injection of forged network commands and packets.
Injection of forged network commands and packets
It is the Impersonation of a legitimate user IP address.
Paralyzation of a network by launching many numbers of ICMP requests
Sending a huge number of ping requests
Launching an overwhelming number of UDP packet
Fabrication of a legitimate user’s data packets using the predicted TCP sequence index.Protocol and paradigm defending security
There are three types of protocol that defend the security
WPAN stands for wireless personal area network. It is used for interconnecting with personal devices (e.g., a keyboard, audio headset, printer, etc.) at a relatively low data rate and within a small coverage area.
WLAN stands for wireless local area network. It is used for connecting wireless devices through an access point (AP) within a local coverage area. Its coverage area is greater than WLAN but less than WMAN.
WMAN stands for wireless metropolitan area network. WMAN provides high coverage area and peak data rates.
Bluetooth is an example of WPAN. The coverage area is 100m and the speed is 2Mb/s.
For security reasons, each Bluetooth device has four entities:
• Bluetooth device address (BD ADDR) contains 48 bits, which is unique for each Bluetooth device.
• 128-bit private authentication key is used for authentication.
• Private encryption key that varies from 8 to 128 bits in length is used for encryption.
• A random number (RAND) is a frequently changing 128-bit pseudo-random number generated by the Bluetooth device itself.
Purpose: authentication, authorization, and encryption.
Bluetooth defines security moods
• Non-secure: where no security procedure is initiated.
• Service-level enforced security: where the security procedure is initiated after establishing a link between the Bluetooth transmitter and receiver.
• Link level enforced security: where the security procedure is initiated before the link’s establishment.
When a Bluetooth device receives an access request from another device, it will first query its security manager with the aid of its radio frequency communications (RFCOMM) or other multiplexing protocols. Then, the security manager has to respond to the query as to whether to allow the access or not by checking both the service database and device database.
• Trusted/Untrusted device
The trusted device category implies that the device has been authenticated and authorized as a trusted and fixed relationship, hence has unrestricted access to all services. On the other hand, although untrusted device authenticates successfully, but has no permanent fixed relationship, so it is restricted to specific services.
• Authenticated/Unauthenticated device
Bluetooth device is successfully authenticated but has not completed any authorization process, it will be considered as an authenticated device. Besides an unauthenticated device failed to authenticate and has limited access to services
• Unknown device If a device has not passed any authentication and authorization process, it is classified as an unknown device.
• The family of Wi-Fi networks mainly based on the IEEE 802.11 b/g standards.
• Most common security protocols in Wi-Fi are referred to as wired equivalent privacy (WEP) proposed in 1999 and Wi-Fi protected access (WPA).
• Security flaws in WEP: can be ‘cracked’ in a few minutes, using a basic laptop computer.
• WPA was proposed in 2003 for replacing WEP. The improved Wi-Fi protected access II (WPA2) constitutes an upgraded version of the WPA standard. Both WPA and WPA2 are using in WIFI modem.
First, an initialization vector (IV) of 24 bits is concatenated to a 40-bit WEP key. This leads to a 64-bit seed for a pseudorandom number generator (PRNG), which is then used for generating the keystream. Additionally, an integrity check algorithm is performed such as a cyclic redundancy check on the plain text to obtain an integrity check value (ICV), which can then be used for protecting the data transmission from malicious tampering. Then, the ICV is concatenated with the plain text, which will be further combined with the aforementioned keystream in modulo-2 for generating the ciphertext. Although WEP carries out both the authentication and encryption functions, it still remains prone to security threats.
• WiMAX (also known as IEEE 802.16) is a standard developed for wireless metropolitan area networks (WMAN) and the initial WiMAX system was designed for providing a peak data rate of 40 Mbps.
WiMAX protocol stack layer
1. Physical (PHY) layer
2. Medium access control (MAC) layer
Mac has the following sublayers:
• Service-specific convergence sub-layer
• The common part sub-layer
• The security sub-layer (security issues and risks are considered and addressed).
• LTE is a standard, developed by the 3G partnership project
• Next-generation mobile networks designed
• Providing seamless coverage
• High data rate
• Low latency
• Supports packet switching
• Includes many new elements such as relay stations, home eNodeB (HeNB) concept, etc.
Classification of LTE
• A LTE network typically consists of
1. An evolved packet core (EPC).
EPC is comprised of a mobility management entity (MME), a serving gateway, a packet data network gateway (PDN GW), and a home subscriber server (HSS).
2. An evolved-universal terrestrial radio access network (E-UTRAN).
The E-UTRAN includes two components, a base station (also termed as eNodeB in LTE) and several user equipment (UEs).
• If channel conditions between the UEs and eNodeB are poor, a relay station may be activated for supporting their data communications. A HeNB may be installed for improving the indoor coverage by increasing both the capacity and reliability of the E-UTRAN.
Physical layer security against eavesdropping
The following physical-layer security is emerging as a promising paradigm designed for improving the security of wireless transmissions.
1. Information-theoretic security
2. Artificial noise aided security
3. Security oriented beamforming
4. Security diversity method 5. Physical layer secret key generation
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