On Mac OS X, Disk Utility provides an option to create a password protected virtual disk image which could be used to place important data files on system or user can burn that image on CD/DVD.

So, in following you can find the method to know that how you can protect your files on Mac by creating a password protected virtual disk image.

How to create password protected virtual disk image

Feb 02, 2014  So, on my external USB hard disk I had created two password-protected '.dmg' disc images. Both functioned normally for about 2 months. Then, suddenly, one of the two images now opens without asking for its password (the other file remains protected).

Step 1

Click on “Finder”.

To launch “Disk Utility” navigate to Applications > Utilities.

Step 2

Click on New Image. How to mount dmg file.

Step 3

On following screen fill the information according to your choice but select Encryption: 128-bit AES encryption (recommended) and click Create button at the bottom. Mac os x download iso.

Step 4

It will prompt for password so enter password and re-type that in Verify field. Un-check the box followed by Remember password in my keychain and press OK.

It will create your virtual disk on desktop with specified name as Personal Disk.dmg. Now double click on it to open.

It’ll ask for Password so provide password and click OK.

On desktop it will mount the Personal Disk Image folder.

So drag your folders or files to this image folder which you want to keep password protected.

To un-mount the created virtual disk, right click on it and press Eject. Convert iso to dmg with poweriso.

Step 5

Make Dmg Bootable Mac

Now you can move your Personal Disk.dmg wherever you want on system or burn to a disk.

Mac Os X Dmg File

A dmg file is a compressed file structure, capable of containing folders, files, etc. Dmg files can be used for a variety of purposes, from encrypting a home directory (ie – FileVault) to encrypting a file structure manually. A dmg file can be encrypted fairly simply. From Disk Utility, create a dmg file by clicking on the File menu and selecting New and then Blank Disk Image. This will bring up a screen where you can provide a name for your home folder and a size, then select either AES 128 or AES 256, which is a bit slower.Go ahead and click on Create and then at the resultant password screen go ahead and provide a password to be used. And let’s just go ahead and uncheck the option to create an entry in Keychain for the password.If you would rather do so from the command line I covered how to do so in a previous post.Now let’s download Spartan, a tool built by Ryan Kubasiak. Now download a dictionary file. I just used one of these (and for expedience sake I paired down the contents to only have about 100 possible passwords, one of which was mine). Now go ahead and open Spartan, clicking on Go! at the splash screen.At the Choose a File screen, browse to and then select your password file, clicking Choose once you have done so. At the next Choose a File screen browse to and then select your dmg file which you would like to crack the password for. The password file will then be read into RAM and the password cracking will commence.According to the length of your password this could take a long, long time, but when it’s done you will have your password, assuming it was in the dictionary of passwords you used. Dictionary files can be downloaded from a variety of sources, some collections taking up gigabytes upon gigabytes of space and covering every possible keyboard combination. Therefore, the longer the password that you use and the more complex the password is, the longer it will take to break the encryption.“So, would your holiness care to change her password?” – The Plague