802.11i and AES
As discussed earlier, WPA was an interim measure designed to take the items ready for prime time out of the 802.11i working group and deploy them in mid 2003. WPA, therefore, was a subset of 802.11i. The primary component of 802.11i that wasn't quite ready was the AES cipher. In the 802.11i specification, however, AES was mandatory, unlike TKIP, which was optional.
Introducing a New Cipher, AES-CCMP
AES is the Federal Information Processing Standards (FIPS) compliant encryption engine designed to be a replacement for RC4. The original adoption of AES by the U.S. government was the result of an extensive search and peer review process.
AES has a variety of modes, but the 802.11i specification has selected the counter mode with ...