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3.2.3.1 Encryption Mode
WPA improves data encryption by using Temporal Key Integrity Protocol (TKIP), Message
Integrity Check (MIC) and IEEE 802.1X. WPA2 use Advanced Encryption Standard (AES) in the
Counter mode with Cipher block chaining Message authentication code Protocol (CCMP) to offer
stronger encryption than TKIP.
The encryption mechanism used for WPA(2) and WPA(2)-PSK are the same. The only difference
between them is that WPA(2)-PSK uses a simple common password, instead of user specific
credentials. The common password approach makes WPA(2)-PSK susceptible to brute-force
password-guessing attacks but it¡s still an improvement over WEP as it employs a consistent,
single, alphanumeric password to derive a PMK which is used to generate unique temporal
encryption keys.
3.2.3.2 IEEE 802.1X Authentication
WPA and WPA2 apply IEEE 802.1X and Extensible Authentication Protocol (EAP) to authenticate
wireless stations using an external RADIUS database. WPA2 reduces the number of key
exchange messages from six to four (CCMP 4 way handshake) and shortens the time required to
connect to a network. Other WPA2 authentication features that are different from WPA include key
caching and pre-authentication.
