Using Encrypted Disk Images in Mac OS 10: A Guide

If you want to keep a few files safe and locked away, but don't need full file encryption like FileVault, creating an encrypted disk image is a great way to do so. To get started, you'll need to use the Disk Utility app, which can be found in the Utilities folder within the Applications folder.

To access Disk Utility, open up a new Finder window and navigate to your hard drive. From there, go into the Applications folder and select Utilities, and then choose Disk Utility. Once opened, you'll see a simple interface with various options for creating and managing disk images.

One of the first things you'll need to do is select "New Image" from the top menu bar. This will allow you to create a new disk image file that can be used for encryption. You'll also have the option to give your image a title, which will be visible when you mount it in Finder. In this case, let's call our image "Disk".

Next, you'll need to choose the size of your disk image. Disk Utility allows you to select from a variety of sizes, including 100 megabytes, or custom sizes in kilobytes, megabytes, gigabytes, or terabytes. For this demo, we'll choose the default 100 megabyte size.

Once you've selected the size of your disk image, keep in mind that once it's created, you won't be able to change it. You also can't add files larger than 100 megabytes if you want to use a smaller size. Additionally, if you try to fill up the disk image with large files, you won't be able to add more files until you delete some of the existing ones.

Now that we have our disk image created, let's move on to the format section. This is where you can choose what type of file system you want to use for your encrypted disk image. Mac OS X supports a variety of formats, including UDRW, UDZO, UDRK, and ISO9660. If you plan on using your encrypted disk image across multiple computers, it's recommended to use the UDRW format.

However, if you're only going to be using this disk image on one computer, there are a few other formats you may want to consider as well. For example, you could choose a Read and Write format for quick access, or a Sparse Image that will grow over time as files are added to it.

Finally, let's select the encryption settings for our disk image. Here, you'll have two options: 128-bit AES encryption, which is recommended for general use, or 256-bit AES encryption, which is much more secure but also slower. Since we're just demoing this, we'll choose the 128-bit AES option.

Under Partitions, select Single Partition and then Master Boot Record partition map. This is the standard setting for disk images created using Disk Utility, and it's what you'll want to use unless you need to create an image for other purposes, such as booting a computer or creating a backup.

Now that we've set all of our options, select "Create" to begin creating your encrypted disk image. You'll be prompted to enter a password, which will be used to encrypt the data on your disk image. Keep in mind that this is not secure - you should never use a weak password like "password"! In this case, we'll just call it "Password", and uncheck the "Remember Password" checkbox so that our password won't be stored in the Keychain.

Once the disk image has been created, you can see it on your desktop as a new file called "Disk". If you open up a new Finder window, you should see the disk image mounted and ready to use. From here, you can drag files into the image, add more files, or delete existing ones. However, if you try to open the image directly in Finder without entering the password, it will prompt you for authentication.

To test this out, let's open up another Finder window and navigate to our encrypted disk image. If we try to open it without entering the password, we'll be prompted to do so. Once we enter the correct password, however, we can access all of the files within the disk image.

"WEBVTTKind: captionsLanguage: enhey everyone today I'm sure how you can keep your files safe by using encrypted disk images in Mac OS 10 line now you might be saying that there's an easier way to do this and that is with file evolve and while filevault is built right into OS 10 and it's easy way to encrypt your files it's not ideal if you only want to keep a few items safe and locked away so that's what i'll be showing you how to do in this video so you're going to need disk utility for this and the easiest way to go define that is to open up a new Finder window go to your hard drive and from there the Applications folder and then utilities and utilities you should find disk utility and you can open that up now in disk utility it's fairly simple all you have to do is select new image and here I can select a title for the image so let's say I want to call this image image now this is the title of the image that you're going to see when the file is on a desktop and under name this is the name of the disk image actually has when you see a mounted in finder so I'll call this one a disk so you can see the difference between over later and then from here I can choose the size of the disk image and there's a whole bunch of different sizes or I can choose custom and then here I can choose sectors kilobytes megabytes gigabytes or terabytes and of course if your drive isn't several terabytes in size you're not going to want to choose several terabytes because it's not going to work much for this demo I'm just going to choose the default 100 megabytes the important word of note is that once you choose the size of the disk image you cannot switch it back after you've created it and you cannot put any files in this image that exceed 100 megabytes and once you've filled it up that's it you can't keep adding more files unless you delete some let me move to be format section now there's a lot of different formats here and any of the mac OS formats will not work on a Windows computer if you choose to use the image on more than one computer well if you want to know more about formats you can check out another video I didn't call the mac and of course i'll have a link to that post below the video of c you can watch that as well and then here's where I can select encryption now there's two different types of encryption and the best one to choose is 128-bit aes encryption that is recommended if you choose something like 256-bit it's incredibly secure but it's much slower and really anything over 128 is that really necessary and then under partitions the thing that I always choose and the best thing in here is single partition and that is the Master Boot Record partition map so this is what's standard and unless you want to use your disk image for other purposes this is what you want to choose and then from here you can choose an image format now the default is read and write this image and that's what we're going to use for this but if you choose something like a sparse image that will actually grow over time as you put files in it which is nice because then you don't have to worry about to be in this case 100 megabytes size limit but for now we'll just leave it like it is and then term here I can select create and it's going to ask me for my password for this demo I'm just going to use password as the password which is not secure at all but it's just the demo and you can see the password train is very weak now I'm going to uncheck remember password on my keychain because if you leave this checked anytime somebody on your computer tries to open this kimmage it'll let them right in because the passwords in your keychain so I'm going to uncheck that and select ok and it's going to create the image rather fast in this case because it's only a hundred megabytes and I'm here on the desktop you can see image that dmg and this is your disk image so if I open up a new Finder window you can see that it's mounted right here and it's just called disk and now I can drag whatever files I would want to into it ml copyright it in and then I can eject the disk and now once the disc is injected if I try to open it up right here you can see it's going to tell me to enter the password before the image so I'll just enter password and now if I open up a new Finder window it'll let me write in and there I can see all my encrypted files so there you go there's how to use encrypted disk images in Mac OS 10 this is a great way to keep some of your more sensitive files safe if you have any how to is that you'd like to see me do make sure send me an email I hope you found this video useful thank you for watchinghey everyone today I'm sure how you can keep your files safe by using encrypted disk images in Mac OS 10 line now you might be saying that there's an easier way to do this and that is with file evolve and while filevault is built right into OS 10 and it's easy way to encrypt your files it's not ideal if you only want to keep a few items safe and locked away so that's what i'll be showing you how to do in this video so you're going to need disk utility for this and the easiest way to go define that is to open up a new Finder window go to your hard drive and from there the Applications folder and then utilities and utilities you should find disk utility and you can open that up now in disk utility it's fairly simple all you have to do is select new image and here I can select a title for the image so let's say I want to call this image image now this is the title of the image that you're going to see when the file is on a desktop and under name this is the name of the disk image actually has when you see a mounted in finder so I'll call this one a disk so you can see the difference between over later and then from here I can choose the size of the disk image and there's a whole bunch of different sizes or I can choose custom and then here I can choose sectors kilobytes megabytes gigabytes or terabytes and of course if your drive isn't several terabytes in size you're not going to want to choose several terabytes because it's not going to work much for this demo I'm just going to choose the default 100 megabytes the important word of note is that once you choose the size of the disk image you cannot switch it back after you've created it and you cannot put any files in this image that exceed 100 megabytes and once you've filled it up that's it you can't keep adding more files unless you delete some let me move to be format section now there's a lot of different formats here and any of the mac OS formats will not work on a Windows computer if you choose to use the image on more than one computer well if you want to know more about formats you can check out another video I didn't call the mac and of course i'll have a link to that post below the video of c you can watch that as well and then here's where I can select encryption now there's two different types of encryption and the best one to choose is 128-bit aes encryption that is recommended if you choose something like 256-bit it's incredibly secure but it's much slower and really anything over 128 is that really necessary and then under partitions the thing that I always choose and the best thing in here is single partition and that is the Master Boot Record partition map so this is what's standard and unless you want to use your disk image for other purposes this is what you want to choose and then from here you can choose an image format now the default is read and write this image and that's what we're going to use for this but if you choose something like a sparse image that will actually grow over time as you put files in it which is nice because then you don't have to worry about to be in this case 100 megabytes size limit but for now we'll just leave it like it is and then term here I can select create and it's going to ask me for my password for this demo I'm just going to use password as the password which is not secure at all but it's just the demo and you can see the password train is very weak now I'm going to uncheck remember password on my keychain because if you leave this checked anytime somebody on your computer tries to open this kimmage it'll let them right in because the passwords in your keychain so I'm going to uncheck that and select ok and it's going to create the image rather fast in this case because it's only a hundred megabytes and I'm here on the desktop you can see image that dmg and this is your disk image so if I open up a new Finder window you can see that it's mounted right here and it's just called disk and now I can drag whatever files I would want to into it ml copyright it in and then I can eject the disk and now once the disc is injected if I try to open it up right here you can see it's going to tell me to enter the password before the image so I'll just enter password and now if I open up a new Finder window it'll let me write in and there I can see all my encrypted files so there you go there's how to use encrypted disk images in Mac OS 10 this is a great way to keep some of your more sensitive files safe if you have any how to is that you'd like to see me do make sure send me an email I hope you found this video useful thank you for watching\n"