Cyber Security: Wifi Encryption

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

Nothing can be done about that!

People can 'eavesdrop' on you when you are using a shared network.

Preventing a Confidentiality Breach

One of the three security essentials in the CIA Triad is confidentiality.

To as ensure confidentiality we need to make sure that the eavesdropper is not able to convert these signals back into the original message.

Preventing a 'man-in-the-middle attack'

A security problem when 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.

Preventing a 'denial-of-service' (DoS) attack

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.

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

Encryption 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.

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.

Encryption in wi-fi transmission

A number of security techniques have been developed to protect wi-fi networks from unauthorised users and to ensure that the data transmitted across them is secure.

Encryption of data shared by wifi is built into routers: See WEP and WPA