How to Password Protect a Microsoft Word Document
Microsoft Word includes two types of password protection. Document encryption completely locks down a document, providing security for sensitive files by preventing unauthorized users from even opening them. Password protection locks document editing but does not stop a user from opening the file, which is useful for documents that do not require security precautions. Word does not contain a method to recover lost passwords, so keep a copy of your code in a secure location.
Encrypt a Document
To lock a document in Word 2013 (and also 2010), open the "File" menu, select the "Info" tab and click "Protect Document." Choose "Encrypt with Password," enter a new password and then enter the password a second time to confirm. Adding encryption prevents anyone from opening the document without the password. This encryption also means that password-protected Word documents will not open in other word processors, such as WordPad or OpenOffice Writer.
Prevent Document Editing
Adding a modification password to a Word document prevents other users from editing the file without a password but does not encrypt the document's contents or prevent viewing. To restrict edits, open the "File" menu and click "Save As." On Word 2013, also click "Computer" and then "Browse" to reach the Save As window. Press "Tools," then "General Options" and enter a password in the "Password to Modify" box. Because this method does not encrypt the file, another user could open the document in an alternate word processor to get around the editing lock, so do not rely on this technique as a security measure.