Secure your data with Encrypted Disk Images

You can’t go far today, if you are a geeky sort without coming across security. Now sure there are some that call themselves geek that take this whole thing just too far. They know the *nix system back to front. I mean, for real, if you need a calculator and you _know_ how to do that on the unix shell prompt, you simply need to get out more – sure we all respect you for your years of dedication but really?

Anyway back to the point.

There is no news flash around this one, its common (if still often overlooked), you _need_ to back up your computer. Currently though there is still a lot of confusion over what to backup and where to place it. I am not going to cover this in the detail that it deserves right here but I am going to give you an insight on how to store your personal, private data, and you will be happy to know that using this method it is not hard, complex, scary or time consuming – in fact once you set it up, its dead easy. Setting it up is actually dead easy as well.

There are a lot of online backup / storage facilities these days, you are a Mac user so so you will undoubtably be familiar with mobileme from Apple. And there are many others that do the same kind of thing from the perspective of allowing you to store files on a remote server, out there on the internet some where (AKA The Cloud).

Many people have a problem with this for one reason. Security.

You have sensitive documents that you want to have control over and you want to store them on some tangible storage that you control, you touch physically and know who else has access to it.

That’s all well and good but does not pass one of the key lessons about backup. Have a copy offsite – your house/office/apartment/where ever you keep a computer can still burn down/be burgled / get dropped etc..

And that is where any kind of Cloud storage comes in. Its remote, chances are if your apartment burns down, you are going to have to be really unlucky to have your preferred supplier also burn down on the same night. (Obviously if you live next to the apple data centre pay no attention to the last statement)

Apple users are very early in their adoption, introduced to the disk image. Loads of software installations are as simple as downloading the image, Finder mounts the image, you drag it into the Applications folder and its done.

You can use the same kind of disk images to store your personal data. You can create an empty image that’s encrypted (seriously encrypted we’re not toying around here) – its password protected – its pretty secure.

Once you create this kind of disk image, sure you can save it on your computer. I in fact do just this. All my important documents that I want to remain secure, even if my laptop is stolen are stored in a disk image like this.

But in addition to this, you can then place this disk image on a remote server to maintain a backup of your secure personal documents. And while its remote, its out there on the internet, while your password is kept to yourself its secure.

So how do you do it? Well its rather straight forward.

Firstly you have to create an empty image.

Use the Disk Utility that comes with OS X. Recent versions of OS X you will find this in the Applications/Utilities folder.

After running the application, select from the main toolbar ‘New Disk Image’. This will allow you to create a new disk image specifying the size and other attributes.

Use the screen shot below as a guide.

• Choose a name for your image
• Choose a location for it – you can move it later no problem
• Volume size if important – you want to store a lot of data choice a size that is going to fit all of your data – mine is 2GB and I have loads of room to go
• Encryption - choose 256 bit, its the best don’t worry about the slower comment, its hardly noticeable
• Finally for Image Format – choose ‘read/write disk image’ otherwise its not going to be very useful at all

Once you click ‘create’ you will see this screen.

Simply enter a password, a good one now, don’t be putting your name or your address in here. Once done you will find that OS X creates the image in the place you selected.

Double click that image and you will be prompted to enter your password, then its mounted in Finder and you can use it like any other disk. Drag files to it, save files to it from inside applications – its easy.

As soon as you unmount it from Finder its encrypted again and no access to it is available without entering your password again.

Now, back to the subject of the Cloud storage services. You can now store this disk image on iDisk (if you use mobileme) or some other cloud storage system as its encrypted and secure.

So you have a backup of your personal documents,it is secure and  it does not cost you a fortune – but it works.