Security is an essential aspect of wireless networks because such networks are a shared and open medium with no default protection so everyone can access it. The solution to confidentiality issues is to encrypt the data that flows through a Wi-Fi environment so that only people who are authorized can transmit and receive data.
The original 802.11 standard was not built with great security features in mind. The first WLAN security mechanism was WEP (Wireless Equivalent Privacy) and it emerged with the 802.11b standard. WEP offers different levels of encryptions, with keys of 64 or 128 bits in size.
WPA (Wi-Fi Protected Access) became available in 2003 and was intended as an intermediate measure in anticipation of the availability of the more secure and complex WPA2. WPA uses dynamic key management, adds a stronger encryption cipher, and is built on the EAP/802.1X mechanism. It uses the Temporal Key Integrity Protocol (TKIP), and the initialization vector has been increased to 48 bits (more than 500 trillion key combinations). Some of the WPA characteristics include the following:
- It is used with RADIUS in the enterprise
- It uses an encrypted hash
- Every packet gets a unique encryption key
Some of the key differences between WPA and WPA2 include the following:
- RC4 encryption is replaced by AES
- TKIP is replaced by CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol)
MAC address filtering involves administrating who will have access to the network based on the Layer 2 address of the devices. This ensures that unauthorized users cannot access network resources and it provides a granular control mechanism within the environment.
If you are administering a wireless network, you will want the signal to cover the entire user area but you do not want it to span across the network boundaries and be accessible by outside users. For security reasons, you should set the signal of the access points as low as possible.