MacMost Now 46: Protecting Files With a Password

Gary Rosenzweig looks at one method to protect a set of files with a password. It involves using Disk Utility to create an encrypted disk image.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: MacMost Now 46: Protecting Files With a Password.

Hi, this is Gary Rosenzweig with MacMost Now. One of the most common questions we get is how do you password protect some files on your drive. For instance you maybe have a folder that's password protected. Now, you gotta ask yourself why your doing this, probably to keep prying eyes from looking at some of your files. In that case the real good way to do it is to actually have a separate user account for these files and maybe other things like applications you don't want other people to be using. But if you don't feel like setting up an entire password protected account on your computer, you really just want protection for your files, the way to do this on leopard is to create a disk image but, create a password protected disk image. Let me tell you about disk images and how to create password protected ones to protect some of your files. To create a new disk image what you need to do is open up disk utility, you can find it in your applications utilities folder. Disk utility is a very handy application that allows you to do lots of things with your hard drives and also your cd and dvd drives. But you can also create these virtual drives which are actually files on your computer that act just like regular hard drives or CDs. So in order to create one you go file and you create a... select new and blank disc image. This brings up a menu here and you can name it and you can also give it a type. Now you got a lot of choices in volume size for instance you can select a hundred megabytes, five hundred megabytes whatever it is you could choose a custom size as well. Lets just do a hundred megabytes. After you've created one you could always adjust the size using this utility as well. But if you want to avoid taking up a hundred megabytes on your real hard drive for this file that will be a disk image one thing you could do is set it to a sparse disk image so it'll look like a hundred megabyte drive but in fact it'll just you the amount of space it needs so it grows the more files you put into it. Next thing you want to do is you want to set an encryption. Now normally I'll set to none which is a standard disk image but, if you set it to 128 bit you'll get the option of password protected. Now we've set up these thing we'll go head and create this drive and it'll prompt us for a password so we're gonna just type in a per week password and you'll have a remember password in my key chain. Okay now if you don't want people to be able to log on this drive easily you wanna uncheck that. Now it's going to create this drive. You'll see it appear on the left. You'll also see that if you go to your documents while this is where we chose to save this we've got this test dot sparse image file there. Also see we have this disk image, remember thats the name we left it, there just as a separate hard drive. It will also appear on your desktop as disk image. We look at it see there's no files there.But now we could go ahead and drop some files on to it, so lets go and find something, drop. We'll launch text edit and create a very simple file.

Comments: 8 Responses to “MacMost Now 46: Protecting Files With a Password”

    11 years ago

    Very useful video Gary, perhaps you can also make one detailing password protection for .Mac. For example, how long does it take to activate and can I password protect more than one file on .Mac at a time?

    10 years ago

    That is great, I have been looking at hiding some files! LOL…!!

    9 years ago

    Hi Gary,

    How do I delete a disk image? Do I have to do it via the utility, or can I simply delete from the directory I saved it in?


      9 years ago

      A disk image, when not open, is just a large file. Delete it as you would any file.

    9 years ago

    Dear Gary,

    I used to have True Crypt to safely store private files. There I could take the box (or disk image containing all my stored files and folders) and open it in another computer (as long as that too had True Crypt installed on it). Saved on Mac I could open it in Windows and vice versa. Does the disk image created on Mac provide the same flexibility?

      9 years ago

      Mac disk images could only be opened on a Mac. I have tried TrueCrypt, but since it requires that TrueCrypt be installed to use it at all, I didn’t find it very useful.

    8 years ago

    will disk image file be lost after Mac OS X erase & install ?

      8 years ago

      ALL of your files will be lost after an erase and install of the OS, if that is what you mean, yes. Only do an erase and install of the OS if you have major problems and all else has failed.

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