What is Message Integrity Check (MIC)?
A. MIC is yet another enhancement to address the vulnerabilities in WEP encryption. MIC prevents bit-flip attacks on encrypted packets. During a bit-flip attack, an intruder intercepts an encrypted message, alters the message and then retransmits the altered message. The receiver does not know that the message is corrupt and not a legitimate one. In order to address this issue, the MIC feature adds a MIC field to the wireless frame. The MIC field provides a frame integrity check that is not vulnerable to the same mathematical shortcomings as the ICV. The MIC also adds a sequence number field to the wireless frame. The AP drops frames received out of order.
