How strong is the encryption on Microsoft Office documents?

Episode 1456 (18:11)

Mike from Riverside, CA
Microsoft Office

Mike is wondering how good the encryption is in Microsoft Word and Excel documents. Leo says it's actually pretty good and that it's adequate, but not uncrackable. Leo says it's hard to crack stuff on the web when a service can slow the attacker down. But if someone can get a document that's locked and own it, there's nothing to stop them from trying a million passwords a second, and brute-force that document. Having said that, Microsoft has started using strong encryption on documents. The weak link will be the password. Leo recommends using a password generator and create a very long random password. If he were to create a 40 character password, that wouldn't be brute-forcible in our lifetime.