Just Works

This model is defined for the scenarios where one or more devices do not have a display to show any pin or any digit. In this model, the user is not shown any digits, rather, a numeric comparison happens and then the user is asked to accept the connection. This model is not secure from man-in-the-middle (MITM) attack , where a person is listening to the channel constantly.

An example of this model is when a cellular phone tries to connect to a headset. At the headset end, there is no display to show the digits. Hence, the numeric comparison happens and the user is just asked to accept the connection.