Wireless Network provides various comfort to end users but actually they are very complex in their working. There are many protocols and technologies working behind to provide a stable connection to users. Data packets traveling through wire provide a sense of security to users as data traveling through wire probably not heard by eavesdroppers.
To secure the wireless connection, we should focus on the following areas –
- Identify endpoint of wireless network and end-users i.e., Authentication.
- Protecting wireless data packets from middleman i.e., Privacy.
- Keeping the wireless data packets intact i.e., Integrity.
We know that wireless clients form an association with Access Points (AP) and transmit data back and forth over the air. As long as all wireless devices follow 802.11 standards, they all coexist. But all wireless devices are not friendly and trustworthy, some rogue devices may be a threat to wireless security. Rogue devices can steal our important data or can cause the unavailability of the network.
Wireless security is ensured by following methods-
- Privacy and Integrity
In this article, we talk about Authentication. There are broadly two types of Authentication process: Wired Equivalent Privacy (WEP), and Extensible Authentication Protocol (802.1x/EAP).
These are explained as following below.
1. Wired Equivalent Privacy (WEP) :
For wireless data transmitting over the air, open authentication provides no security.
WEP uses the RC4 cipher algorithm for making every frame encrypted. The RC4 cipher also encrypts data at the sender side and decrypt data at the receiving site, using a string of bits as key called WEP key.
WEP key can be used as an authentication method or encryption tool. A client can associate with AP only if it has the correct WEP key. AP tests the knowledge of the WEP key by using a challenge phrase. The client encrypts the phrase with his own key and send back to AP. AP compares the received encrypted frame with his own encrypted phrase. If both matches, access to the association is granted.
2. Extensible Authentication Protocol (802.1x/EAP) :
In WEP authentication, authentication of the wireless clients takes place locally at AP. But Scenario gets changed with 802.1x. A dedicated authentication server is added to the infrastructure. There is the participation of three devices –
- Supplicant –
Device requesting access.
- Authenticator –
Device that provides access to network usually a Wlan controller (WLC).
- Authentication Server –
Device that takes client credentials and deny or grant access.
EAP is further of four types with some amendments over each other –
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