When it comes to securing access through open SSIDs, the best way is to have the captive portal in place. Its the perfect way to to build a zero trust network,

When it comes to securing access through open SSIDs, the best way is to have the captive portal in place. Its the perfect way to to build a zero trust network, where in you don't trust anyone who connects to the SSID and is forced to authenticate through the captive portal. Put captive portal in place and force the users to validate through their phone numbers, social media accounts or emails. You can even integrate your existing IdP to the captive portal and even ask your employees to connect through the captive portal.