Do you have files on your Mac that you want to keep safe from prying eyes, or from someone who steals your laptop? I keep a spreadsheet file with all my online passwords written in it, and I don’t want that file accessed by someone who steals my laptop, or looks at my computer without my knowledge. There are two ways to keep files safe on your Mac: a simple way, and more secure but complicated way.

The safer but more of a hassle solution is to use the built in application called FileVault, that can encrypt your entire Home folder. It is serious encryption so if you forget your password, you’re files are gone forever. It can be turned on in System Preferences. Sometimes though, this extra secure method can cause problems with other computer applications needing access to files inside your home folder, or if you share files in your home folder with other computers on your network. Maybe you are like me and don’t want the entire home folder protected, just a few files. If so, there is an easier way to keep files safe on the Mac.

Using Disk Utility, you can create a password protected file that can you can drag and drop files into, and this works great when you only want part of your files protected, not your entire computer.

Start by opening the Disk Utility in your applications (or sometimes Utilities folder). Once it is opened, go to the File menu and select New -> Blank Disk Image. This will open up a new window and your Mac will ask you to name the new file you are about to create. I personally like to name it something random, like “untitled” or “junk” to avoid suspicion. Don’t name it: “My secret passwords!” Select the Desktop as the place to save it to.

Skip down farther to Name and make this name a more descriptive one, like Passwords or Financial Data. This name won’t appear until after the correct password is entered, so you can afford to be more name appropriate. Next, for size, choose a size that will hold all the files you want to keep safe. If you just want a password file, 40 MB will be ample, but if you want to save a lot in there, choose something larger. If you run out of space in the future, you can always create a new, larger protected file like we are now, and put all your files into the larger one.

Format should be Mac OS Extended (Journaled). Encryption should be 128-bit AES. Partitions should be set to Single Partition – Apple Partition Map. And finally, Image Format should be “Sparse Disk Image.” With these settings, click Create.

Disk Utility will now ask for a password that you will need to type when opening your new disk image. It will also tell you how strong or weak your password is. Type a password that shows as “Excellent” under password strength. Type it in again and click OK.

In just a few seconds, your new file (disk image) will be created and you will have two new icons on your desktop that look like this:

The .sparse-image file will be titled whatever you named your file when you first created it, and the icon that looks like a removable disk or flash drive will be named the more descriptive title. To make sure you did everything correctly, drag the removable disk to the trash to eject it, or click on it once to highlight it and hold down Command-E to eject it. Then, double click on the .sparse-image file and it should ask you for the password you just created and once that it entered, the removable disk appears again. If you double-click on the removable drive, it opens like a folder would.  Important!  When you enter the password, the “Save this password to your keychain” box is automatically selected.  Deselect this.  If it is checked, the computer will automatically remember your password and not ask you for it when you open the .sparse-image. You do not want this as it defeats the point of having to enter a password to access files.

Drag any files you want safe into the drive and be aware that this copies the files into that removable disk just as if you had plugged in a flash drive and were copying files to a flash drive. If you have a secret password file on your desktop and drag it to the removable disk, the file will exist in two places — the drive, and the desktop, because it was copied over, not moved over. After copying a file to the drive, delete the original file from the desktop, or it will remain out in the open for prying eyes. When all the files you want safe are copied over to the drive and then deleted from their original location, drag the drive to the trash to eject it, or highlight it and hold down Command-E.

It’s vitally important to remember not to throw away the .sparse-image file, as it can deleted! On Mac’s, if you drag a removable disk to the trash, the trash becomes and eject icon, but if you drag a file (like the .sparse-image) to the trash, you aren’t ejecting it, you are putting it in the trash. Only “delete” or eject the drive file. You can keep others from viewing your data, but not from deleting your data with this method. In other words, people could delete your .sparse-image file, but never actually access it without the password. To help you remember to not delete the .sparse-image file by mistakenly dragging it to the trash instead of the removable disk, click on the .sparse-image file once to highlight it and then go to File -> Get Info, or hold down Command-I. This opens up an informational window where you can put a check mark next to the option “Locked.” This will remind you with a warning dialogue box that it shouldn’t be thrown away if you accidentally put it in the trash. Also, it will not allow anyone who does not have admin access to your computer to delete it. If you are the only user, you are logged in as the administrator and can delete it by accident. Be careful!

When you double-click the .sparse-image file and type your password, the removable drive file appears. You can now access your important data and use it like a normal file. When you are finished, quit the programs you used to access your secure files and then eject the drive file. With it ejected, no one can now access your .sparse-image without having the password you set up. Always remember to eject the drive when you are finished working with your secret files, or they will be exposed. You can put the .sparse-image file anywhere you wish, preferably buried in a few ambiguous folders. Enjoy keeping your important data safe with your new .sparse-image file.

TobyLaura.com