Ways to Secure Files in Mac OS X

AppleMatters recently published an article detailing the three primary ways of protecting your data: invisibility, passwords, and encryption. Each of these provides some security, but at much different levels.

• Invisibility:  If you make files or folders invisible, other users can’t see them. This method is quick and easy.  However, this is the least secure method, as a skilled user can still find your files.  There are programs (such as HideOut and Secret Folder) to assist you if you want to use this method.

• Password and Encryption Options: 

Create an encrypted disk image with password protection
This method is free, relatively easy, and very secure.  To make a secure disk image, first open up Disk Utility and click on the New Image icon. Next, choose where you want it to be saved. This next part is very important: you must select the size you want your image to be — too small and you will fill it up too quickly / too big and you will waste lots of space on your machine.  After deciding the size be sure to set the encryption to “AES-128″ and you can leave the format as read/write. Finally, click create, enter the password, and you are done. Now you can copy your files/folders onto the image. When you’re done, eject the image. From that point on, opening it will require the password.

Create a separate user account using FileVault for secure data
This method is secure, very easy, and free, but it requires lots of space, requires fast-user-switching to be turned on, and only works if you use the administrator password.  To use this method, you simply create a new user account and dump all of your secure files into it. To gain access to files from your “main” account, use fast-user-switching and the “shared” folder to swap files. Of course, this method requires all the overhead associated with creating a new user. And lest we forget, the system administrator would still have access to your files. But other than those slight problems it will work just fine.

Use iCrypt
This option isn’t free and bugs can cause data loss, but it is very simple, very secure, and doesn’t require lots of hard drive space.  iCrypt, a shareware program, does exactly what you expect and nothing more.  To use it, you open the program, set your preferences, and then drag-and-drop to encrypt files. The encrypted files are self-extracting, which means that you can encrypt the file, send it to someone else, and as long as that person has the password, the file will be decoded as it opens.

Source:  "Ways to Secure Files in OS X" by James R. Stoup, published at AppleMatters.