What protocol is primarily used to secure user authentication in modern WLANs?

The primary protocol used to secure user authentication in modern WLANs is IEEE 802.1x. This protocol provides a means for robust authentication in a network setting, allowing devices to request access to a network and enabling the network to respond with the necessary credentials for validation. It operates in conjunction with various authentication methods, including EAP (Extensible Authentication Protocol), and is often employed in enterprise environments to securely manage device access to the network.

Other protocols, such as WPA2, while providing encryption and security measures for wireless communications, rely on IEEE 802.1x for user authentication in environments that require strong access controls. Therefore, while WPA2 enhances the security of the data transmission itself, it is the 802.1x standard that specifically facilitates the authentication process necessary to control access to the WLAN. This distinction highlights why IEEE 802.1x is seen as the cornerstone of user authentication in modern wireless networks.