Compute a new GTK and install it alongs
        MIC (AP -> Group = broadcast + multicast)

def install_GTK(self):
        """Compute a new GTK and install it alongs
        MIC (AP -> Group = broadcast + multicast)
        """

        # Compute GTK
        self.gtk_full = self.gen_nonce(32)
        self.gtk = self.gtk_full[:16]

        # Extract derivated keys
        self.mic_ap_to_group = self.gtk_full[16:24]

        # Reset IV
        self.group_iv = count()