Securely Delete Files from Your Mac Easily

August 1, 2010 | By | Reply More

Reading time: 4 – 6 minutes

How to ensure that your confidential data is securely erased from your Mac? It is not good enough to just delete files and empty trash. When you delete a file in your Mac hard drive, only the file reference deleted. The file remains intact on the drive. You will not be able to find a deleted file using Finder, because Mac OS X cannot locate and access the deleted file since file’s reference is missing.

For extremely sensitive data, you need to use tools that will ensure, beyond any doubt, that your data has been completely erased and is beyond any possible hope of recovery.

How To Permanently Shred Mac Files?

The only way to ensure that your file can never be recovered again is to shred the file. File shredder Mac does not refer to tearing up your file into tiny pieces, though that is the metaphoric reference we are using here.

File shredder Mac refers to overwriting the traces of your deleted file, or your entire hard drive, repeatedly until no trace of the original data remains.
Note that before you shred your files, you must be very sure that you will not need any of that data ever again.

Shred Selected Files Using Secure Empty Trash Option

If you want to permanently erase selected files, use the Secure Empty Trash option. To do this:
1. Move the files you want to permanently erase on your computer to the Trash.
2. From the Finder menu, click Secure Empty Trash.
3. Click OK if you want to continue with the deletion(s). This method erases all your data.

Data that has been shred using this method is not easily recoverable, and if recovered, only delivers a lot of garbage. However, there are some truly sophisticated and therefore frighteningly expensive tools out there that can retrieve data that has been wiped out using the Secure Empty Trash method.
It is best to follow up this method with a permanent eraser action, which might be a little time-consuming, but worthwhile.

Using Mac OS X Disk Utility To Shred Mac Files

To completely erase a Macintosh hard drive that runs OS X 10.3.x or above (not just individual files, but the whole drive) use the Disk Utility that is built into the Macintosh operating system.

Note: Erasing a hard drive deletes all the volumes and files on the drive. Therefore, before you erase the hard drive, if you want to keep files on the drive, copy them to a form of external media.

To permanently shred files in your Mac OSX:
1. Reboot your computer using the OS X system CD that came with your Mac, as follows:
a. Insert the CD into the CD drive.
b. Hold down the C key during the startup process.
2. Select your preferred language; you will see the Welcome to the Mac OS X Installer window.
3. From the Installer Menu Bar, click Open Disk Utility. The Disk Utility window opens.
4. From the left pane of the Disk Utility window, select the drive you want to erase.
5. In the right pane of the Disk Utility window, open the Erase tab.
6. From the Volume Format drop-down menu, select Mac OS Extended (Journaled).
7. In the Name field, highlight the existing text and type the name you want to call the hard drive after it is formatted.
8. In the Erase tab, select one of the following security options:
• Do not Erase Data: This option only rewrites the headers on the disk and is NOT secure. Note that your files can be recovered by forensics, disk utilities, and other advanced recovery software.
• Zero Out Data: This option is secure for most commercial use. Note that data can still be recovered by sophisticated forensics utilities. There is no documented evidence to this fact, however.
• 7-Pass Erase: This option is considered secure enough, going by Government standards. It writes random data over the disk seven times, taking several hours to complete the process.
• 35-Pass Erase: This is the most secure option available on your Mac to shred data permanently. Using this option ensures that it is absolutely impossible to regain any data off the drive. This option takes an extremely long time, possibly more than one day.
9. Click the radio button in front of 7-Pass Erase
10. Click OK.
11. Click Erase.
Confirm your action; the program will unmount the volume, partition the drive, and rename the volume to the name you provided. Once this is done, leave the machine to do its work. Do not close the lid of your laptop.

This article for the MacKeeper is a guest post by Callins. The above software is not duly tested by The Editor.

Tags: , , ,

Category: guest post

Leave a Reply