Mac: How To Encrypt An External Hard Drive In Lion

Most computer users use or carry around some kind of portable hard drive or flash disk these days. Considering how we use our computers, almost all of those portable drives tend to store an alarming amount of sensitive data. Have you ever thought what would happen if you lose the disk and the data gets into the wrong hands ?

There are a lot of software solutions available that’ll let you encrypt the data on your disks but most of them are confusing to use and just a pain really. Not, if you’re a Mac OS X user.

Mac OS X lets you encrypt and password protect the contents of any connected disk. Follow our little guide to know how.

First of all, if it wasn’t obvious, connect your disk (using USB) to your Mac and launch the Disk Utility application.

The Disk Utility application will display all the drives that OS X has recognized on your computer in the sidebar. Select the drive that you want to encrypt.

Note: To Encrypt a drive, OS X has to format it and so you will lose all the existing data on the drive. If there is any important data on the drive, copy it to another location and then copy it back later.

Now, select the Erase tab and from the Format drop down list select “Mac OS Extended (Journaled, Encrypted).

You can also select the Case-Sensitive, Journaled, Encrypted option if you want your file system to be case sensitive.

Now, click the Erase button.

Disk Utility will now ask you to enter a password that you will use to access the contents of the encrypted disk. If you can’t think of a strong and memorable password yourself, I’d definitely suggest using the Password Assistant. Click on the little key icon next to the password text box and play around with the password assistant till you find a nice password that you can remember and one that is secure.

That’s it. Now, wait for Disk Utility to finish partitioning and encrypting the disk.

When the disk is ready for use, as indicated by Disk Utility, I’d suggest that you eject it and insert it again just to check if everything works as it should. If you followed the procedure properly, Mac OS X will ask you for a password to access your disk when you insert it again.

That’s it. Enter your password and you should be able to access the contents of your disk as always. When you’re finished using the disk, make sure you eject it properly so that no one else with access to your computer can access your data.

The only problem with this method of encrypting your external hard disks is that the data on the disk can only be viewed on a Mac OS X computer. Depending on your preferences, though, that may well be a good thing!


How To Recover Data From a Memory Card

Memory Cards are as much a part of our daily computing as hard disks and RAM is. The Digital cameras that we use everyday, the mobile phones that we rely on and even some of those tiny netbooks that we use, more often than not use some kind of memory card based storage to store data.

Improvements in technology have made memory cards pretty reliable but there are times when even the best technology fails and when that times comes, you’d be glad to have included a memory card data recovery software in your toolkit.

Since, I’m a Mac OS X user, I’ll be talking about data recovery software that you can use on a Mac to recover data from corrupted memory cards, but there are similar software available for almost all platforms and in fact, the open source program that I’m going to walk you through today is available for Windows and Linux also.

To get started, download TestDisk from CGSecurity. Both the tools are distributed in a single tar.bz2 bundle named after TestDisk, so don’t look too hard if you can’t find PhotoRec on the CGSecurity site. I downloaded version 6.12 since I don’t have Rosetta installed on my Mac. If you have Rosetta installed, download the 6.11 stable version and that should also work for you.

Open the archive and since both of these are command line based tools, launch Terminal and browse over to the directory where you extracted the files.

Run the PhotoRec utility from the command line like this

darkstar:testdisk-6.12-WIP sharninder$ ./photorec

Select the disk that you want to recover data from and hit enter.

The next step is to select the type of partition table that the disk/memory card has. If this disk was being used on a regular PC, it’d most likely have an Intel type partition table, or if you like me use an Intel based Mac then you’d have an EFI/GPT type partition table. If the disk that you’re trying to recover data from is a memory card, it’d most likely be using the Intel partition table format. Select the appropriate choice and hit the enter key.

PhotoRec will now search the hard disk for any partitions of the selected type and display them on the next screen. Select a partition from the list and proceed.

The next step is to choose the type of filesystem. For a memory card, this would most likely be FAT, so select “Other” and hit enter. Photorec will now ask you to select a directory on your system where the recovered files will be saved. Use the arrow keys to to move to whichever directory you want and press ‘C’.

Photorec will now start scanning the entire disk and will save any files that it finds to the directory that you selected earlier.

Let me warn you, though, this is a very long process and scanning an entire disk can take anywhere from a few minutes to a few hours depending on the size of the disk.

The process is also not fool proof. Depending on how much the disk has been used after deleting a particular file, you may or may not be able to recover all your deleted files. This is not Photorec’s fault, though. This is just how filesystems on most modern operating systems work.

Mac: How To Create An Encrypted Disk To Securely Store Your Data

Disk UtilityApple likes to claim that Mac OS X is one of the most secure operating systems available.

While it may be true that a default install of OS X, is usually more secure than a similar default install of a consumer Linux distribution, it is also true that the average Mac OS X user is far less computer savvy than an average Linux user. A default OS X install has almost no open network ports and even secure encrypted services such as ssh have to be started manually for the first time after installation. This, in my opinion, does make OS X a much safer bet for a home user than, say, Windows or even Linux.

But, if you’re still paranoid about securing your data and would like to store all your data encrypted on your computer, OS X has ways to do that also. OS X lets you create an encrypted volume on your computer that you can use to store your data. Access to this volume is through a password and without the password all an attacker would get access to is encrypted junk.

Disk Utility

To create an encrypted disk image, launch the Disk Utility application that is bundled with OS X and click on the New Image button. Make sure that you don’t select any volume from the sidebar when you click the New Image button as that will tell Disk Utility to create a copy of that volume instead.

Disk Utility

Select a name and size for your new disk and from the Encryption drop down select an encryption scheme. Apple offers two encryption schemes, 128-bit AES and 256-bit AES. Choose the one that suits you. Select Read/Write Image from the image format drop down and click on the Create button.

Disk Utility will then prompt you to enter a password. You can even use a password assistant that can help you create a reasonably strong password. Store the password in your keychain, if it’s too hard to remember it.

That’s it !

Disk Utility will now create a disk image and once it’s done, it’ll be mounted for you to use it for the first time. Copy your data to this Volume and unmount it to keep it away from prying eyes. The next time you double click on the disk image, OS X will ask for a password to open it for you.