Which client-access method requires user authentication and can operate without link-layer encryption?

WebAuth (Web Authentication) is a client-access method that redirects users to a web portal for authentication (username/password). It operates at a higher layer and does not inherently provide link-layer encryption, relying on existing network encryption or secure protocols like HTTPS for the authentication portal itself. WEP (Wired Equivalent Privacy) is an older wireless security protocol that provides both authentication and link-layer encryption, but it is highly insecure. PSK (Pre-Shared Key) is used in WPA/WPA2/WPA3 for authentication and also provides strong link-layer encryption. "Open" authentication means no authentication is required, and typically no link-layer encryption is used, which contradicts the requirement for user authentication.