Originally Posted by
deniah
Protection on microsoft documents can be easily defeated using a brute-force scheme.
Since Office 2007, Office document encryption has used AES-128. It's quite secure (well, as secure as Microsoft's implementation and your password).
Originally Posted by
TOMFORD
I don't know of a simple way to password protect a file, but you can put your passwords on a sheet in an Excel, hide the sheet, then put a password for unhiding sheets (or altering Excel structures).
VeraCrypt