Password protect files and folders
You can protect all the files on your Mac by encrypting a Vault (or entire drive) with FileVault.
If you consider FileVault a bit of an overkill for your purposes, you can password protect your files and folders in different ways.
iWork suite documents
If you have Pages, Keynote, or Numbers files with sensitive information, you can password protect those files.
Open the file you want to protect
Go to File -> Set Password
Enter a Password
Verify the password
If you want a hint to help you remember your password, enter a Password Hint
Set Password
PDF Files in Preview
Open the PDF file you want to protect (does not work for image files)
Go to the File menu and then press the Option key. The Duplicate menu option becomes Save As.
Select the Save As option.
On the Save dialog box, check the Encrypt box towards the bottom.
Enter a Password
Verify the password
Save
To remove the password protection from a PDF file, open the file, enter the password, use the Option key to access the Save As option again and uncheck the Encrypt option on the Save dialog box. Save the file with a new name and delete the old password protected file.
Microsoft Word files
Open the Word file you want to protect
Click the Review tab, and then click Protect Document
On the Password Protect dialog box, enter
Password
Optionally require a Password to modify the document
Optionally add other Protection to the document
Optionally Remove personal information from this file on save
Save
Microsoft PowerPoint and Excel files
Password protecting a Microsoft Excel workbook is similar to protecting a PowerPoint presentation, but the dialog box is different.
Go to File -> Passwords
Under Password to open, check the “Encrypt this presentation and require a password to open” box.
On the Set a password for this presentation dialog box, enter
New password
Verify the password
Click Set Password
OK
To remove the password from the presentation, open it, go to File -> Passwords, and uncheck the “Encrypt this presentation and require a password to open” box.
Password protect folders
Disk Utility can erase, format, repair, and partition hard drives. It can also can create an encrypted disk image, or a single file that contains the entire contents of a drive or other media like external USB drives, CDs, or DVDs.
Copy the files you want to protect into a folder
Open Disk Utility
Go to File -> New Image -> Image from Folder
Select the folder you want to encrypt and click Choose.
In box enter
Enter a name for the disk image in the Save As box
Where to store the DMG file
Encryption type (128-bit or 256-bit AES) (Enter a Password and then Verify the password)
Select read/write from the Image Format dropdown list
Save
A progress dialog box appears and a message saying that the operation was successful
Click Done
Use Eraser to securely delete the original files
Disk Utility adds the disk image to your desktop. Double-click the disk image icon to access the files inside it. To access the files you added to the disk image, double-click on the DMG file and enter the password when prompted. Eject the disk image when you’re done using it, so the files are password protected again.