Sending a file to Trash is pretty simple on the Mac, and there are a variety of ways to do it. Holding the command key and tapping delete on the keyboard, clicking on File in the Menu Bar and selecting Move to Trash, or the most common, clicking and dragging the file to the Trash icon in your dock. After you “empty” the Trash, those files are gone forever, right? Not really. Sometimes when a user needs to be sure a file is really erased—a sensitive document or financial information, for example—an extra step should be taken to ensure files are really gone.
Delete isn’t actually deleting?
As is the case with most hard drives, files aren’t actually gone when they’re deleted. On the plus side, this means you can save your files from the void if you accidentally delete them. It also means that files which most would rather have permanently deleted can be resurrected.
Instead of immediately wiping a file, a hard drive simply marks a file from “protect this block of information,” into “feel free to write over this information.” Depending on how many files are written to a drive, how large the files are, and other various circumstances, a file could actually stick around on a hard drive for a very long time after being “deleted.”
Securely erase files
Mac users have a pretty easy time of securely deleting files. After a file, or group of files, is moved to the trash, in the Finder menu, select Secure Empty Trash. This command will mark the files as deleted, but will also write zeroes to the hard drive, making file recovery much more difficult. Since files are actually being written to the drive, instead of simply being marked as “able to be written over, “Secure Empty Trash” takes longer than the regular Empty Trash command but can help if you really don’t want those files brought back to life.
Securely format a hard drive
Instead of simply throwing a hard drive or computer in the trash, think about either recycling it through a recycling program or donating it to a local school or charity. Before donating the machine, however, you’ll want to securely erase the data from the hard drives so that your data doesn’t end up in someone else’s hands.
Much the same way that deleting a file doesn’t actually remove all the data, formatting a hard drive also doesn’t overwrite all the data either. Typically when a hard drive is “formatted,” areas of the disk are simply defined into logical groupings and some sort of index defines how the disk is divvied up. Formatting a hard drive adjusts the index to the new specifications, but doesn’t actually touch the data.
Fortunately, there are tools to scrap the data. For all OS users, I recommend pulling the hard drive, if possible, and connecting it to another computer you can boot from. This will ensure that you’re able to erase the old hard drive from the computer you’re currently using. If that’s not possible, try to find a bootable disc, (like an operating system disc, or Disc 1 of the two gray discs that came with your Mac) then simply head to Disk Utility, select the hard drive/partition you’d like to erase, and then select the “erase” tab. Click on the Security Options button. Once there, you’ll find a list of options for securely erasing a hard drive.
The first simply zeroes out the data. This process is relatively quick, though much slower than a standard “format,” and will provide an adequate amount of security on deleted data.
To go the extra mile, OS X provides users with two other options including a seven pass erase, which writes random characters seven times over, or a 35-pass erase, which writes and rewrites data 35 times over. If we were getting rid of one of our main work computers that contained our financial records or other sensitive material, we’d likely set the erase for the 35 pass erase and let the computer do its thing overnight. No point in not being as secure as possible.
Once the set of passes is complete you’ll have a hard drive ready to be sold, donated, traded or anything else you’d like to do with it, without having to worry about your information ending up on someone else’s computer.
Here’s a very useful little app, especially for those who (like me) choose to ride a bike to work, and who choose to listen to music during that commute. Noise-canceling headphones and sound-isolating earbuds are exciting technologies, but what happens when the sound you’re isolating out is the car horn of the vehicle behind you trying not to run you down? That’s where this baby comes in hand.
