Here are a few ways to protect sensitive data within your Excel workbook:

File Level Protection:

* Encrypt with Password: This is the most common method. You can set a password on the entire workbook, restricting anyone from opening it without the password.
* Read-only Password: You can create two passwords: one to open the file read-only (view data but not modify) and another with full access for editing.

Worksheet Protection:

* Protect Structure and Window: This prevents users from modifying the worksheet structure (hiding/deleting rows/columns) or freezing panes.
* Restrict Specific Cells: You can lock specific cells or ranges, allowing users to edit other areas while safeguarding sensitive data.

Other Methods:

* Hide Rows or Columns: This can be used to hide sensitive data but remember hidden information can still be accessed through certain methods.
* Remove Sensitive Data Before Sharing: If possible, consider removing the sensitive data entirely before sharing the workbook with others.

Important Considerations:

* Password Strength: Choose strong passwords and keep them confidential. Lost passwords cannot be recovered by Microsoft.
* Limited Access: Grant access only to those who genuinely need it.
* Complementary Measures: These methods work best in conjunction with other security practices like storing your files on secure platforms.