Sep 30

One can apply AES in many different ways. The way that the 802.11i standard has chosen to apply AES is with CCMP, which is based on CBCMAC. CCMP was chosen for data integrity and authentication, with the Message Authentication Code (MAC) providing the same functionality as the Message Integrity Check (MIC) used for TKIP. Before diving into CCMP, one needs to look at AES and some of its modes. The first term is CTR; this is AES in Counter mode. This mode is used for confidentiality. The next mode is called CBC-MAC, which stands for Cipher Block Chaining Message Authentication mode. This mode is used for integrity. AES also has combined CTR and CBC-MAC to create CCM. CCM is the acronym for CTR/CBC-MAC mode of AES that incorporates both the confidentially of CTR and the integrity of CBC-MAC.