Your computer’s hard drive contains an extraordinary amount of personal information; information that an identity thief could use to commit financial, criminal and medical fraud under your identity. So when you are considering selling or throwing away an old computer, naturally, you delete everything off of your hard drive. But is that enough?
There are different methods of “deleting” information off of your hard drive and not all of them actually delete anything. Data is encoded onto a hard drive by magnetizing strips of material that the computer can later retrieve by reading the magnetic pattern encoded into the disk. To permanently delete information, the magnetic code must be fully removed from the disk.
Recycle or Trash Bin
Most people delete files and information off of their computer by dragging or sending the file to the recycle or trash bin and then emptying it. This is misleading because that information is not actually deleted. When a file is “deleted” in this manner, the computer does not remove the magnetic information from the disk, but instead makes that space on the disk available for information to be stored. Thus, you may think you deleted a file, but in actuality the information is still encoded into your hard drive and could be retrieved by someone else unless your computer happened to write over that information when you saved something else.
Physical Destruction or Degaussing of Hard Drive
There are two ways you can destroy the hard drive to ensure the data stored on it is unrecoverable. One, you can smash the hard drive yourself with a hammer or other tool, but you run the risk of leaving some information that is recoverable if you do not do a thorough enough of a job. There are many companies who provide shredding machines capable of reducing a hard drive into a pile of scrap metal, fully eliminating any ability to recover any information.
Another way to permanently delete information off of the hard drive is to degauss it. Degaussing is a process by which magnetic fields are either reduced or eliminated. Unfortunately, this method of permanent deletion will also damage your hard drive, rendering it incapable of storing information in the future. Obviously, the downside to these methods is that you will not be able to sell or use the hard drive ever again, but at least you know your data is gone forever.
Electronic shredding is the process in which information is deleted off of a hard drive by rewriting information over the old information multiple times. This is a form of formatting the hard drive, but is more thorough due to the multiple rewrites and the pseudorandom data that is used to write over the old information. The multiple rewrites continually erode any old magnetic fields coded into the disk until they are unrecoverable. Some programs permanently delete individual files or folders and others permanently delete the entire hard drive. It is recommended that if you are throwing away or selling your computer to use the electronic shredding program that wipes your entire hard drive. This ensures that no personal information is left on your hard drive in the case that some of your personal information is in a file or folder that you forget to individually delete.
The bottom line here is that when you are releasing control of your hard drive, you need to make sure that all of your personal information is permanently erased or destroyed to avoid identity theft and fraud.
"Electronic Shredding – Get Rid of Ghost Data" was written by Sam Imandoust, Esq. He serves as a legal analyst for the Identity Theft Resource Center. We welcome you to post/reprint the above article, as written, giving credit to the author and linking back to the original posting.