Archive for 12 August 2004
One of the great things about iPods and iRivers (and the iHP-140 in particular 
) is that they’re basically a hard disk in a very small box – which means that you can do what you’d normally do with a hard disk, i.e. write data to it. So as well as being an MP3 player, it’s also a detachable and very portable backup hard drive.
The only downside to this is that there’s no security built into the device, so should anyone wander off with it, they’ve also wandered off with all your data in a plaintext format. Not ideal. So I’ve been looking for a way of encrypting the files on the external drive as a way of protecting them, without necessarily lumbering myself with added complexity.
Fortunately (insert smug grin here) I’m using a Mac and OS X, which makes the whole process pretty much foolproof (or me-proof, which amounts to much the same thing). Originally I’d thought of creating an encrypted disk image in the Powerbook’s hard drive, and then copying this over to the iRiver. The problem with this would be that I’d have to copy the entire image across every time a single file changed, which is not exactly quick. Then it occurred to me – what if I created the encrypted image on the iRiver itself, and merely treated it as another disk that I’d dump files onto? Problem solved. As far as I know, there’s no reason why this shouldn’t work on an iPod, but I ent got one, so I ent tested it…
The process goes something like this:
- Attach the iRiver in the normal way
- Run Disk Utility and create a new image of the desired size, making sure to select the AES encryption option
- When the new encrpyted image has been created, mount it in the same way you would mount any disk image
- Use your backup software of choice (I’m using ChronoSync, for example) to backup files from the Mac to the newly-mounted encrypted image on the iRiver.
- When you’ve finished, unmount the encrypted image.
The net effect of all this is that you end up creating an encrypted disk image which to anyone not in the know, just looks like one very large file. Even assuming that they did know what the file was, the fact that it’s wrapped up in AES-128 encryption means that it’s going to take them a dauntingly long time to get at it.
The only downside of this is that you lose the ability to read the encrypted disk image if you’re connecting the iRiver to a PC, PCs not knowing about such things. This isn’t such a problem for me, given that I tend not to use it as a means of hauling data around, but if there’s a utility out there that allows .dmg images to be opened under Windows, it’ll sort this issue. I shall embark on some Googling to see if it’s possible…
find IHP-140/ -name filename -print -delete
