Issues And Challenges In Wireless Network Security

Models of wireless networks

Wireless network is operating under infrastructure mode, such as 802.11, 802.16, and Cellular networks. Ad-hoc network is operated without infrastructural support. Network has the open nature of communication that is a security issue for network itself. There are two main issues in the network are Authentication and privacy. Network is also having other issues like denial of service (referred as DOS) attack (Mukherjee, Fakoorian, Huang, & Swindlehurst, 2014).

We have different wireless technologies for making communication better, such as Wi-Fi, WI-MAX, Wireless USB, and many more. Wi-Fi is used for short-range mobile access network and Wireless Local Area Networks (referred as LAN). For broadband connectivity of systems, Wi-MAX technology is used. There are other technologies also for connection making, such as infrared, Gigabit wireless. Infrastructure of a network is based on different criteria, such as fixed infrastructure, Ad-hoc wireless networks, and mixed mode networks. In case of fixed infrastructure, base station is used for; provide network to mobile nodes, such as sensor network and cellular network. In case of ad-hoc network, there are no needs of infrastructural supports. Mobility of nodes is allowed, such as laptops and mobile operating in ad-hoc mode (Tahir & Loo, 2009). In case of mixed mode, any devices take both modes as per requirement. A proper model is follow for designing a network such as lightweight and local control in a network. Some difficulties of wireless network as compared to wired networks are transmission, interference, resource constraints, mobility, and physical carrier sensing. In next parts of this report, I will discuss about wireless networks models, different layers of TCP/IP suite and issues and challenges with solutions (Liang & Yu, 2015).

Unit disk graph model

In this model, u and v are nodes and R is radius of network. This is simple models for connecting different nodes in a network.

If d(u,v) <= R  than u and v are connected. They can have transmission rights in that network.

In this model, we can manage arbitrary shapes of different nodes. This model is widely used in many organizations. It is must to communicate u and v that they are in transmission range r_t.

This model facing many problems, such as interference problems in wireless network, such as node w can still interfere at node u. for this problem, made changes in transmission and interference range. Sometimes extension of unit disk model is also used for handle interference.  

Security solutions of issues in networks

Physical layer

802.11 standards support several data rates between 11 Mbps to 54 Mbps in a network for different nodes. 802.16 standards support different data rates from 2 Mbps to 300 Mbps for different nodes in a network. Many modulation techniques are used for various conditions and data rates, such as PSK, BPSK, QPSK, OFDM, OFDMA, and many more.

Red nodes are distrusting routes for other nodes.

Some technologies are used as a standard for wireless communication are:

• 11a – working on 5 GHz using OFDM
• It has 4-8 non-overlapping channels for network and bandwidth of this channel is 54 Mbps.
• 11b – working on 2.4 GHz frequency using Direct Sequence Spread Spectrum (DSSS)
• It has three non-overlapping channels for network and bandwidth of this standard is 11 Mbps.
• 11g working on 2.4 GHz frequency and it used OFDM for transmission.

It archive 54 Mbps data rate and it is inter-operable to 802.11b.

Media Access Control (referred as MAC) layer

This layer has different functions, such as scanning, authentication, fragmentation, and Request to Send / Clear to send (referred as RTS/CTS). It is used Collision detection. It is not possible in wired networks, hence it use collision avoidance to remove interference problems. In case of 802.11 MAC physical carriers, carrier sensing is used to sense of multiple medium for a free medium, but some hidden nodes are there and it will be a collision. For avoiding this problem use virtual carrier sensing using RTS/CTS (Kumar & Lee, 2011).

Network layer

Network layer route packets in the network. It is as IP routing based on infrastructure networks. At network layer handoff, problem issues are solved by Wi-MAX technique. In case of ad-hoc, network problems are solved by proactive and reactive manner, such as DSR, DSDV, and AODV (Pathan, Lee, & Hong, 2006).

Transport layer

In this layer wireless medium, face high bit-error rate and collision problems. Using TCP reliability mechanism handled this type of problems. Maximum of this type of errors handled by physical layer using FEC and other error correcting codes, such as linear code, hamming code, and block codes.

Application layer

In this layer, protocols of this layer are facing problems, such as email, web, games, sms, and MMS.

A big problem at MAC layer is DOS, which means sending noise in the medium continuously. It can be done without draining the power of the network. It is totally depends on physical carrier sensing threshold. Solution of this problem is Access Control Lists (referred as ACL) for admission control. It means if your system mac address is not in list, the node is do not access that particular network (Jain, 2011).

In case of Network layer in ad-hoc networks have many issues, such as packet dropping, packet rerouting, DOS attacks, and broadcast nature of communication. Broadcast nature of communication means all nodes in the transmission range can receive each message. In case of wireless networks, packet sniffing is much easier. For this issue, uses intelligence switches for stopping broadcasting of packets, which is unnecessary. One huge problem in network layer is route discovery in wireless networks, such as ad-hoc network created by laptops or mobile phones. AODV discover the path for data transfer by RREQ and RREP. It still has some adversarial nodes. They can fail route discovery. Another issue in network layer is packet dropping. In case of wired network, it can be monitor reasonably but in case of wireless network such mechanism are resource intensive. Packet rerouting will help for such type of issues. Different types of firewalls and filters are useful for not infected from this type of problems.

Cryptography can help in that type of issues at high level, such as public key solutions but they are slow compared to symmetric key operations. Symmetric key is the best solution for privacy and authentication. RC4 is well documented for authentication and privacy (Römer, Kasten, & Mattern, 2002). Authentication is depending on encryption techniques, if weak encryption technique is used then authentication is also weak (Giruka, Singhal, Royalty, & Varanasi, 2008).

Rivest Cipher 4 (referred as RC4) is a stream cipher in cryptography. It is also known as ARCFOUR. It is so good in speed in software. In starting, it is a trade secret, but after sometimes, it is posted in cypherpunks and sci.crypt news groups.  Until 2015, it is highly used in many encryption techniques. It was prohibited by RFC 7465 for all versions of transport layer security. RC4 generate a keystream, which consist of two parts are a permutation of all 256 possible bytes and 2 index-pointer of 8-bits (Tahir & Loo, 2009).

A secure communication is necessary between base station and node for privacy. 802.16 networks use a specific certificate for authentication, such as X.509. It provide a public key certificate to secure subscriber station authentication for security. It establishes security association and also used authentication Key exchange for better security. 802.16 also use AES in CCM mode for privacy and authentication (Du & Chen, 2008).

Remote Authentication Dial-In User Service (RADIUS) type authentication cannot use by ad-hoc networks. If they used RADIUS type authentication, than every node will need to store every other node information. Problem is that mutual authentication is facing trouble in some cases. Ad-hoc networks used proactive mechanism for security. It is like cryptographic mechanism. It secure network by routing attacks. It is also used reactive mechanism for packet forwarding attacks. In wireless network, two scenarios are there, first is broadcast network and second is peer-to-peer network (Bikos & Sklavos, 2013).  

In wireless network, situations are more complex as compare to wired networks. Many issues occurred at different layer of TCP/IPs network architecture. These are challenges for current security mechanism. For securing wireless network, security policies have more encryption techniques to avoid attacks (Akyildiz & Kasimoglu, 2004).  

Conclusion

It is concluded from previous parts of this report that, wireless networks are having many issues and challenges for security. I was discussed about many security issues and challenges of wireless networks, as well as security policies, such as RC4, cryptography, and many more. It is also concluded that different types of attacks can be avoided if a network have a proper security authentication and privacy policies for outsiders.   

Finally, it is concluded that, current security policies are not sufficient for future, so develop new ways to secure wireless networks. Wireless network is so useful and better than wired network in many aspects, but it has many security issues more than wired network.

Akyildiz, I. F., & Kasimoglu, I. H. (2004). Wireless sensor and actor? networks: research challenges. Ad hoc networks, 2(4), 351-367.

Bikos, A. N., & Sklavos, N. (2013). LTE/SAE Security Issues on 4G Wireless Networks. IEEE Security & Privacy, 11(2), 55-62.

Du, X., & Chen, H. H. (2008). Security in wireless sensor networks. IEEE Wireless Communications, 15(4), 1.

Giruka, V. C., Singhal, M., Royalty, J., & Varanasi, S. (2008). Security in wireless sensor networks. Wireless communications and mobile computing 8, 8(1), 1-24.

Jain, M. K. (2011). Wireless sensor networks: Security issues and challenges. International Journal of Computer and Information Technology, 2(1), 62-67.

Kumar, P., & Lee, H. J. (2011). Security issues in healthcare applications using wireless medical sensor networks: A survey. Sensors, 12(1), 55-91.

Liang, C., & Yu, F. R. (2015). Wireless network virtualization: A survey, some research issues and challenges. IEEE Communications Surveys & Tutorials, 17(1), 358-380.

Mukherjee, A., Fakoorian, S. A., Huang, J., & Swindlehurst, A. L. (2014). Principles of physical layer security in multiuser wireless networks: A survey. A survey. IEEE Communications Surveys & Tutorials, 16(3), 1550-1576.

Pathan, A. K., Lee, H. W., & Hong, C. S. (2006). Security in wireless sensor networks: issues and challenges. In Advanced Communication Technology, 2006. ICACT 2006, 2(1), 6.

Perrig, A., Stankovic, J., & Wagner, D. (2004). Security in wireless sensor networks. Communications of the ACM, 47(6), 53-57.

Römer, K., Kasten, O., & Mattern, F. (2002). Middleware challenges for wireless sensor networks. ACM SIGMOBILE Mobile Computing and Communications Review, 6(4), 59-61.

Tahir , N., & Loo, K.-K. (2009). Common security issues and challenges in wireless sensor networks and IEEE 802.11 wireless mesh networks. International Journal of Digital Content Technology and its Applications, 3(1), 1-6.