Claro me respondo de mi mismo a mi pregunta:
"Reaver performs a brute force attack against the AP, attempting every possible combination in order to guess the AP's 8 digit pin number. Since the pin numbers are all numeric, there are 10^8 (100,000,000) possible values for any given pin number. However, because the last digit of the pin is a checksum value which can be calculated based on the previous 7 digits, that key space is reduced to 10^7 (10,000,000) possible values"
