Wireless Technology

Wireless technology - what is it?

It is the transmission of data and/or voice from one location to another with the help of technology that does not the require physical cable.

Wireless network unlike its wired counterpart does not require the use of cable instead, it uses radio frequency (RF) transmissions, that is, wire network has cable linking network with clients whereas wireless networks make use of wireless access points (WAP) and wireless network interface cards (NIC) that are installed in each client to communicate between two points.

This is made possible because wireless technology, like all transmission media, uses radiation as its means of transmitting data through space, that is, wireless technology uses electromagnetic radiation to transmit data because it does not require a medium to transfer the energy from one point to another.

Reason for the growth of Wireless Technology

Wireless technology is expanding dramatically in recent times. This is primarily due to low cost/affordability, ease of installation, mobility and flexibility which has resulted to increased productivity by employees to the benefit of organisations. This also makes it popular with small office and home market.

How it operates

In wireless technology, the wireless network communication is typically governed by a communication protocol – 802.11 series. Each WAP installed on a network broadcast in an omni-directional pattern (i.e in all direction). Any client computer not physically linked to the network must therefore be logically and virtually docked in to the network through the access point using its network interface card (NIC). It is also important to mention that the client also has the capacity to broadcast into the air like WAP.

Every WAPs computer has a unique identifier known as service set identifier (SSID) which is a name or description that is used to differentiate a network from another.

Security issues with Wireless Technology

1) Rogue Access Points (APs)

These are now a more common occurrence due to their low cost and easy installation. Rogue APs are WAPs that are installed on the network by end users without going through the authorised channels.

2) Traffic Analysis and Eavesdropping

Without actually gaing access to the network, it is possible for an unauthorised parties to passively capture the data traversing the network especially if it is not encrypted or when a strong encryption like WPA is not used. This is also known as the Man-in-the-middle. By default, wireless networks send data unencrypted or poorly encrypted e.g when WEP (Wired Equivalent Privacy) that is not so strong is used over the airwaves.

3) MAC Spoofing and Session Hijacking

Wireless 802.11 networks by design do not authenticate frames, and this may result in the frames being altered, or outright hijacked by unauthorised persons where they are likely to assume the role of the sender of the message.

4) Broadcast signal power of the WAP

If not regulated may go beyond the areas covered by the wireless clients thereby given rooms for unauthorised persons to be aware of the existence of the network. Note: By design and out of necessity, WAP repeatedly sends out signals also known as identifier broadcasting to announce their presence so end users can find them to initiate connectivity.

5) Denial of Service (DoS)

This is a situation where an attacker attempts to disable the target network from serving its legitimate users. This can be achieved by setting up another transmitter to operate on the same frequency with the legitimate one but with an overwhelming power so that the legitimate transmitter is subdued.

Some useful security tips

According to Dr. Richard A. Stanley of Wheeler Associates Limited, he said “Security is not an absolute. It is impossible to provide unbreakable security, whether in a wireless network or even in a military setting. No matter how hard one tries, if an adversary is willing to devote sufficient resources to overcoming the defences, he/she will succeed. The security goal is to make it either too costly for an adversary to attack the system, or to provide an incentive for the attacker to attack another system”

i) Isolate the wireless network from other networks, and the resources (data inclusive) available to it should be restricted to what is absolutely required.

ii) Allow only computers with registered MAC (Media Access Control) to access the network. (Note that this can be fooled hence, it must be used in conjunction with other controls.

iii) Activate available security features on your wireless equipment as a starting point in security control. This is because embedded security are disabled by default. This point is very important for small office and home users.

iv) Put in place proper authentication controls.

v) Use any good encryption technology (to protect the confidentiality of data), for example:

a) Wireless Protected Access (WPA) is a stronger alternative to Wired Equivalent Privacy (WEP).

b) Encrypt WLAN traffic using a virtual private network (VPN). This is really good when the data traversing the network are sensitive.

c) Direct all traffic through the VPN server and configure clients appropriately.

vi) Do not broadcast the SSID (i.e turn off identifier broadcasting). Change the default settings of e.g service set identifier (SSID). Change the SSID regularly, where practicable. Always verify the media access control (MAC) address upon device connection.

vii) Install wireless firewall on WLAN

viii) Install intrusion detection systems on the network. Because of the level of mobility of wireless computers, it might be necessary to also install an host firewall on the client to check the activities of unauthorised users.

ix) Install wireless anti-virus and anti spyware on the wireless network.

x) Activating basic security measures at the application level on the network is a recommended best practice. These are some of the things that should be put in place:

a) Implement an application-level user authentication system.

b) Maintain and enforce permission and password policies.

c) Install vendor patches as they become available.

Wireless Technology is still evolving and further development is likely to be witnessed in the coming years.