A malicious user is sniffing a busy encrypted wireless network waiting for an authorized client to connect to it. Only after an authorized client has connected and the hacker was able to capture the…

A malicious user is sniffing a busy encrypted wireless network waiting for an authorized client to connect to it. Only after an authorized client has connected and the hacker was able to capture the client handshake with the AP can the hacker begin a brute force attack to discover the encryption key. Which of the following attacks is taking place?