Add secure additional workbook and worksheet protection Use MS account

Excel only gives you two main built-in protection methods:

1. Worksheet/Workbook protection with a password → (weak, easy to crack, mostly for accidental edits).
2. File-level encryption with a password (File → Info → Protect Workbook → Encrypt with Password) → (stronger, but still password-based).
3. Enterprise features like Azure Information Protection / Purview / IRM → (very secure, but requires enterprise subscription + admin setup).

At present, there’s no way to natively tie workbook/worksheet protection to a Microsoft Account login without using Azure Information Protection / Purview. Microsoft hasn’t built that exact "identity-based protection" option into personal or standard Excel — protection is either password-based (local) or cloud-managed via enterprise licensing.

The “identity-based encryption” you’re describing would require Excel to request decryption keys from Microsoft’s key service every time you open a file, tied to your Microsoft Account session. That’s exactly what Azure RMS / IRM does today, but not what personal Excel does out of the box.

If you want to share Excel files securely without weak password protection but without full enterprise rights management, here are the most realistic current options:

• Store the workbook in OneDrive or SharePoint, share via MS account permissions
• Use "Encrypt with Password" + Require MS Account for access
• IRM / Purview (if you’re in a corporate environment)

What you’re describing is actually a feature request that would sit in between “weak password protection” and “enterprise IRM”.

That doesn’t exist in Excel today. The closest is storing/sharing files through OneDrive/SharePoint with account restrictions, or using IRM in Microsoft 365 Enterprise.

My answers are voluntary and without guarantee!

Hope this will help you.