Disk space: free doesn’t mean blank

Let’s repeat, when you delete sensitive files from a disk on your computer, Windows does not erase the contents of these files from the disk - it only deletes 'references' to these files from file system tables. Contents of the deleted file continue to be stored on the disk space and can be easily recovered using any unerasing utility.  

Download evaluation version of QuickWiper from www.quickwiper.com

Sensitive data – erase it. Is this all?

As you know sensitive data in files you deleted does not physically vanish from your hard disk.

Maybe practically present moment your computer contents a hundreds of “deleted” files contained confidential, secure information, which should not be shared with irrelevant persons. However this may take place: you may sell your computer or hard disk, recharge it or simply provide it to other person in use. It is scared how it’s simple to lose your data.

There are some ways to prevent it and wipe sensitive information from HDD. To wipe is to delete or remove the information from a hard disk in such a manner that it cannot be restored neither processing on computers with the help special software nor with the help of laboratory means (even studying of surfaces of magnetic plates with the help of scanning microscopy).  

First is only defragment your hard drive by standard utility provided by any operating system. As result you get only wiped the unused areas of the data area on the drive.  It will not wipe slack space on files with this operation. But, if you defragment your hard drive - that is to say reorganize the data blocks on your drive, the computer will likely overwrite any residual deleted files that are still on the hard drive. The process can take from a few minutes to several hours depending on the size and type of hard disk.

However, it doesn’t mean an intruder can not get access to sensitive data. Of course, it more difficult way to restore information, but it’s possible in any way by using special equipment and techniques, such as magnetic force microscopy or magnetic force scanning tunneling microscopy.

To more security level you may format your hard drive. It means disk space will be overwrited with service information over your data. But, even this case, most of sensitive data will stay on carrier.

If your information costs great value, you should do more for you security and prevent any access to you sensitive data.

How to permanently wipe data from a hard drive?

The general concept behind an overwriting scheme is to flip each magnetic domain on the disk back and forth as much as possible (this is the basic idea behind degaussing) without writing the same pattern twice in a row. We could simply choose the desired overwrite pattern of ones and zeroes and write it repeatedly. It would mean the drive would lose track of where it was in the data. To wipe magnetic media, we need to overwrite it many times with alternating patterns in order to expose it to a magnetic field oscillating fast enough that it does the desired flipping of the magnetic domains in a reasonable amount of time.

Now there is some simple way to wipe information stored on HDD. At present software method of wiping is most safe, simple and inexpensive. There are a great mass of special software providing to wipe disk space. Most of them are freely accessible in Internet. We just stop at one of that utilities.

QuickWiper is an utility especially have developed by AKS-Labs to securely wipe all data from any hard or floppy drive, regardless of its file format or operating system. It will completely overwrite and destroy all existing data on a disk. Every physical byte of the disk will be overwritten. It includes most known national governmental standards for HDD data destruction and algorithms by authoritative experts in computer data security. This program will permanently wipe and destroy all data. You may overwrite the disk as many times as you like so conforming NSA requirements will not be a problem. Once QuickWiper has been run, all data from every sector will have been eliminated.

Another thing to consider is the file name, location and date/timestamps. Even if you can erase the data itself, the information about the file may still be accessible in system files somewhere, giving the attacker some information on the deleted files. QuickWiper is capable of also erasing the filename and related information from the administration table.

So why QuickWiper?

Along with long time disk wiping (it depends on number of passes) and using only serviceable HDD, it is to note some preferences of software method to wipe disk space.

1.        High reliability. To recover wiped data intruder should be apply such means actually may cost much more, than information to be recovered.

2.        Low price of software (or special means, if needed). This is presented as a great preference along with highest level of disk space wiping.

3.        Possibility of using of hard disk for the second time.

As result we have most interesting method of free disk space wiping, including absolute destruction of sensitive information.  

Related articles:

• Points on information storage and security. At present IT-corporations invests millions of dollar in development of information security techniques. But the only problem is researching how to make public information accessible to all users, and confidential data accessible only to whom it’s intended.

• Short review on non-software methods of destruction of the information on hard drives. Sometimes, when the highest reliability is needed, it’s using mechanical and other methods of destruction of the information, when HDD is breaking as oneself.

• Wipe file and clear disk space. All kinds of information is stored in computers as a files. Each file takes some place on a hard disk. And the first (and main for our issue) problem is you never know where it’s placed, and how much disk space it occupy.

• Disk space: free doesn’t mean blank. Let’s repeat, when you delete sensitive files from a disk on your computer, Windows does not erase the contents of these files from the disk - it only deletes 'references' to these files from file system tables. Contents of the deleted file continue to be stored on the disk space and can be easily recovered using any unerasing utility.