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Securing your documents is important, particularly when sharing them externally.

There are a number of ways to ‘Share’ documents saved in Office 365 (OneDrive or SharePoint), some more secure than others…. but sometimes you want to lock down a specific file so that it’s secure no matter where it’s saved or sent to.

Password protection is useful, particularly if tied with file encryption that renders the file useless unless you have the password – just make it a strong one!

There’s no need to pay for Pro Versions of Adobe Acrobat to do this, or use free, unsecure online PDF editing software… who knows where that data ends up! Microsoft Office has built in functionality to encrypt Office documents and PDF files, locking them behind a password.

How Secure is it?

Older versions of Office password protection (Office 95 and 2003) haven’t got the best reputation and were easy to crack with Google Docs or other easily available tools. However, since Office 2007, Microsoft made huge improvements.

With the latest version of Office, 128-bit encryption is used. Provided you use a strong password, this is very secure.


Use Encryption! Make sure you choose the option to Encrypt the document with the password – Microsoft Office also includes options to ‘protect’ the document with a password. This is to stop people editing the document without entering the password, but does not encrypt it. It’s useful, but does not secure the data in the document.

Use the current file format! Be sure to save to the current XML file format if saving an Office Document (eg: .docx or .xlsx, NOT .doc etc). Older versions of Office documents will have the old protection… which, as I’ve mentioned above, isn’t great.

DO NOT FORGET YOUR PASSWORD! As the encryption is tied to the password protection, you NEED the password in order to decrypt the document. If you forget the password, you can’t access the document. Simple as that… there’s no way around it. This is particularly important if you’re protecting a core business document and saving it in your shared company area… if you are the only person in the company who knows the password, and you leave, then no-one else can get into the document.


Password Protect a Microsoft Office Document

If you want to keep the file in it’s Office document format (Word, Excel, PowerPoint)… With the file open in the appropriate Office application, click on ‘File’ in the top left of the application window and go to the ‘Info’ pane.

Click on ‘Protect Document’ in Word (in Excel, it’s Protect Workbook and in PowerPoint it’s Protect Presentation) and be sure to select ‘Encrypt with Password’.

Enter the password you want to secure the document with and click OK – make it a strong one that you can remember and be sure you let anyone else know that may need to access the document.

You’re all done. When someone tries to open the document, they’ll be prompted to enter the password before they can view the document.

Password Protect a PDF with Microsoft Office

Sometimes you want to send a PDF version of a document to someone, but secure it with a password. This can be done with Microsoft Office too.

Have your document open in Microsoft Word and click the ‘File’ menu, as above… then go to ‘Export’ and click on ‘Create PDF/XPS’ to create a PDF version of your document.

To add the password protected encryption, click on ‘Options’ at the bottom of the new window and then select ‘Encrypt the Document with a password’ and click OK.

Enter the a good strong, and memorable, password and click OK and then give the PDF a name and choose where you want to save it – Then click Publish to save the PDF.

Like with the Office document, you won’t be able to view the PDF unless you know the password.

This encrypted PDF should be viewable in any PDF reader application, such as Acrobat, or even web browser based plugins. It’ll work on mobile too!