How to Shred DATA in the Digital Era

 

 

If you handle a lot of sensitive personal data on your PC, how can you be sure that once wipe the data, it is completely gone?

The analogy of a sensitive message written on a piece of paper is worth considering. To get rid of it, you can crumple it up and throw it away. You could also shred it in a number of different ways, or you could totally destroy the paper by burning it or mixing it in water to create a dough.

In the first case, if you have access to the trash, it is quite easy to take the paper out and make it flat enough to be able to read it. For shredded paper, if you are patient enough, you could put the pieces back together, with time and a suitable adhesive surface. For totally destroyed paper it is almost impossible to restore it and find out what its content was.

Similar sensitive information deletion options are available for data on a PC. You can wipe data, but it can be easily recovered from the Recycle Bin. Even if you empty the container, the data persists on its hard drive and a simple recovery tool like PC Inspector File Recovery can get it back.

Even if the data has been overwritten, it is possible to use similar software to recover it. Therefore, deleting sensitive information in such a simple way is as safe as throwing a piece of paper in the trash.

Methods to safely wipe sensitive information

Method 1. Demagnetize

This process is used to make data unrecoverable from removed hard drives and other magnetic media. A modern degausser is basically a giant box that generates a powerful magnetic field, disorienting the existing magnetic domains of the medium. Usually this is extremely reliable - there is a caveat to the effect that the latest generation hard drives are denser than their forebears and therefore require more magnetic force to fully degauss, but the current generation demagnetizers will remain suitable for use for a time.

Degaussing has, unfortunately, a couple of drawbacks. For starters, it is effective only on magnetic media. A degausser may be powerful enough to erase a 100-terabyte hard drive, but put a flash storage device there and it will come out unscathed.

Second, degaussed hard drives cannot be reused, so it is not an ideal solution for companies looking to recycle or sell their hardware.

 

 

Method 2. Grind

There are some specialized document shredding companies, such as allsafedocuments.es , that offer shredding services. With the use of powerful machines, they destroy not only paper documents, but memories, hard drives, CDs, etc.

In this way, it would be practically impossible for someone to put the pieces together and rebuild it, even more so when the crushed pieces are mixed with each other, making it impossible to differentiate one from the other.

You could also buy a shredder for your own use, but it would be too expensive an investment and it is not always more profitable than hiring a shredding service. In addition, these document destruction companies usually give you a certificate proving that the documents have been destroyed, which can come in handy in case you have to legally prove it.

Method 3. Data Wiping software.

One of the simplest ways to permanently wipe sensitive information is to use DATA Prevention Loss software. Hard drives, flash storage devices, and virtual environments can be erased without specialized hardware, and the required software ranges as the Unistal’s Data Wipe command included with most Unix-like operating systems, to commercial products.

While different data destruction applications use different techniques, they all adhere to a single principle: overwrite the information stored in the medium with something else. Therefore, a program can go through a hard disk sector by sector and exchange each bit for a zero, or with randomly generated data. To ensure that no trace of the original magnetic pattern remains, this is usually done multiple times: common algorithms include the seven-step Scheier, as well as the even more rigorous 35-step Gutmann method.

Unfortunately, there are some drawbacks to software-based data erasure. For one thing, it is quite slow. Then, perhaps more significantly, there is the fact that if certain sectors of the hard drive are rendered inaccessible by normal means, the application will not be able to write them. However, it will be possible for someone with the right tools to recover data from a bad sector.

Obviously, software-based data erasure is also not a good option when you want to destroy information stored on media that can only be written once, such as most optical discs.