Microsoft Office has protected documents with passwords since Word 2.0 in 1991, and for most of that history the protection was weaker than stated. The word “password” in Office covers two completely different things. One is encryption, and it can be strong. The other is a flag that tells the application to refuse an edit, and it has never been strong, because it cannot be. Confusing the two is the most common mistake we see, and it is the reason a document someone was sure they had locked often opens in seconds.