Gamified Intelligent Cyber Aptitude and Skills Training (GICAST)
Gamified Intelligent Cyber Aptitude and Skills Training (GICAST)

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Gamified Intelligent Cyber Aptitude and Skills Training (GICAST)

2.2 Encryption in wireless networking

Described image
Figure _unit5.2.2 Figure 6

Since wireless networks transmit data over a medium that is shared by everyone, anyone with a compatible receiver or transceiver is able to eavesdrop on the radio signals being sent.

Ensuring that the eavesdropper is not able to convert these signals into the original message is a desirable security property of any wireless network, referred to as ensuring confidentiality. (This was one of the three security essentials we mentioned earlier, along with integrity and availability.)

Another security problem with using a shared medium for transmission is that malicious users could interpose themselves between a sender and a receiver and modify the messages being exchanged or even destroy them entirely. This is sometimes called a ‘man-in-the-middle attack’, and it compromises the integrity of the data being transmitted across the network.

Finally, an attacker could transmit lots of random data on the frequency being used by the wireless network, congesting the network and thus preventing other users from sending data. As we saw earlier in the course, this is called a ‘denial-of-service’ (DoS) attack and is an example of an attack on the availability of the network.

How encryption can help

So how do wireless networks address these potential security issues?

One commonly used security mechanism is encryption, which can help to ensure both the confidentiality and the integrity of data. The idea of encryption is to take the information you wish to protect and transform it into a different form, such that only the people who are supposed to receive the information are able to reverse the transformation and recover the original information. This is like having a key to unlock a door; only a person with the right key can open it.

Encryption can help ensure:

  • Confidentiality – When a message is encrypted using a particular key, it can only be decrypted to recover the original information if the same key is used. This ensures that messages are confidential between the sender and the receiver.
  • Integrity – Encryption can prevent messages from being modified without the receiver’s knowledge.
  • Authentication – Encryption can contribute to the process of proving the identities of the sender and receiver.

You will look at encryption and decryption in more detail next week when we explain how cryptography works.

Encryption in wi-fi

Since wi-fi was first introduced, a number of security techniques have been used to protect wi-fi networks from unauthorised users and to ensure that the data transmitted across them is secure. The most common methods are based on encryption, using a key known only to the nodes in the wireless network.

The first of these mechanisms was called Wired Equivalent Privacy (WEP), which (as the name suggests) aimed to provide confidentiality comparable to that of a wired network. Since 2001, a number of serious problems have been identified in WEP that allow the encryption key to be computed within a few minutes, using readily available software. Many wireless devices still support WEP to ensure compatibility with older equipment such as old modems, but wherever possible users should switch to a more modern form of encryption.

At the present time, the recommended security mechanism for wi-fi networks is Wi-fi Protected Access 2 (WPA2), which uses a more secure key to encrypt the transmitted data. This security mechanism has become the default configuration for wi-fi networks, and must be supported by all wi-fi devices in order for them to be compliant with the 802.11 standard.

In the next section you’ll consider how you might use wi-fi more securely.

CYBER_B2

Take your learning further371

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses372.

If you are new to university level study, we offer two introductory routes to our qualifications. Find out Where to take your learning next?373 You could either choose to start with an Access courses374or an open box module, which allows you to count your previous learning towards an Open University qualification.

Not ready for University study then browse over 1000 free courses on OpenLearn375 and sign up to our newsletter376 to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371