It is simply OAuth Based Authentication for Office clients against Office 365. It enables:
- Multi-Factor authentication
- Support for third party STSes
- Conditional Access
Supported across platform:
- iOS, OS X
Modern Authentication Client Support
Office Client Updates
Modern Authentication rely heavily on how much Office clients applications are patched. The first thing to troubleshoot is to make sure that the client is fully patched with the latest Public Updates [PU].
Nowadays, Public Updates [PU] are released every month and they include all previous updates. So If we are in October, if you installed October PU it will include all previous updates
PUs include two types of updates:
- Security updates: Patch Tuesday
- Non-security updates: 1st Tuesday of the month.
You can go here to see information about PU for each month. Normally you care about PU of the current month as it includes everything before.
Now, we are moving from MSI version of Office clients apps to Click-to-Run (C2R) which includes not only updates every month, but also new features every month to catch on Office 365 new monthly features.
Also Click-to-Run comes with new Change Release Management approach by introducing different channels [Branches] to release those updates.
Why Modern Authentication NOW?
We have now Outlook and one way to authentication, and we have other apps like Excel, word, and others, which are using different way to authenticate.
We need a common platform for authentication, so that when you log to PowerPoint, you need also to be able to access OneDrive for example. So Single Sign On is something we want to ensure.
So now we are moving from application authentication to common authentication which is [MSO.dll] and the new one which is ADAL.dll which is used by modern authentication.