Learn how to lock and password protect a folder in Mac OS X so your files stay confidential and in place where you left them.
Select a folder you would like to protect and right click the folder.? Select Get Info and unlock the small icon in the bottom right hand corner.? You may be prompted for your system password.
Look who has access to the folder and restrict everyone to either “Write Only (Drop Box)” or select their name and use the negative symbol directly on the bottom left to remove permissions to the folder.
Next, scroll up and choose to make this folder “Locked.”? This will protect it from being moved or deleted without your permission.
Another way is to create a .dmg of the folder.? Open up the ?Disk Utility? application and navigate to File -> New -> Disk Image from Folder.? Choose the folder you would like to protect and select to protect it with ?AES-128″ encryption.? Enter in a new password and it will create a .dmg which you can open with new password protection.