Modern authentication is a process that allows you to use multi-factor authentication (MFA) and single sign-on (SSO) with Office 365. It allows users to authenticate with their Office 365 credentials, and provides additional security by using tokens and certificates for authentication.
To enable modern authentication for Office 365, you need to set the following registry keys on client computers:
1. On the client computer, open the registry editor (regedit).
2. Navigate to the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\16.0\Common\Identity\EnableADAL
3. Set the value of EnableADAL to 1.
4. Close the registry editor.
Note: The registry key path may vary depending on the version of Office that you are using. For example, if you are using Office 2013, the key path would be HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\15.0\Common\Identity\EnableADAL.After setting these registry keys, you need to sign out of Office and sign back in for the changes to take effect.
It’s important to note that modern authentication is not enabled by default for Office 365. You need to enable it manually using the above steps. Additionally, modern authentication is only supported for Office 2013 or later.