davethefish1
07-26-2008, 01:45 PM
Mon, 04/14/2008 - 21:47 — j.brock From Gizmo
We’ve all heard the horror stories about someone buying a used hard drive at a flea market or garage sale and then finding tons of personal data left on the drive by the previous owner. Or even worse, people getting their credit trashed by ID thieves that make their living by taking that information and using it to wipe you out financially. “That would never happen to me” you say. “I’ll delete all the files first” or “I’ll re-format the drive before I trade it in or sell it.” Not so fast there Scooter! That data you think you erased is still stored on the drive.
When you delete a file it isn’t really removed from the disk. The operating system (OS) only removes the reference to the file from the file allocation table. This is like going into a book or magazine and removing a chapter reference from the table of contents. The actual chapter is still in the book. The only thing removed was the page number reference in the table of contents. With the file location reference removed the OS now sees that disk space as being available for use. However, the file content remains on the disk until another file is written over it.
Basically the same thing happens when you re-format a hard drive. Most of the data remains; the space on the drive is just made available to be written over.
The DOS and Windows file systems use groups of disk sectors, known as clusters, to store data. These clusters are of a fixed size which is normally determined by the size and number of partitions of the disk volume itself and the file system being used. If the data you’re storing requires less space than a full cluster, the entire cluster is still reserved. For example, you’ve saved a file that required 15.5 clusters of drive space. Because the OS can’t reserve a half cluster, the allocation table had to reserve 16 whole clusters for the file. That remaining half cluster that was not used may still contain data from a previous file. That unused half cluster is known as “slack space”. Data recovery programs can read slack space and retrieve the data stored there. Even worse, let’s say the file system places your 15.5 cluster file over the “unused” area of a deleted file that originally took up 35 clusters. More than half of the previous file would still be retrievable! You could have thousands of clusters on your hard drive (a.k.a free space) that contain data you thought was deleted! Scary thought, huh?
The only true and permanent way to make data irretrievable is to completely and utterly destroy the hard drive. That action is probably a little more severe than you or I need. We really only need to make sure we are protected from data recovery programs and the like. That’s where the programs in this category come into play.
To be as safe as possible, you must overwrite (erase) both slack space and free space. Also, the Windows swap file (a.k.a page file) could contain private data that you wouldn’t want to have fall into the wrong hands.
Eraser will securely erase selected files and folders, or even whole disks, located on your hard drive (it works with any drive, including IDE, SCSI and RAID, and CD-RWs). Eraser can overwrite the data area with your choice of a variety of random data patterns, and can also wipe data in the paging file, Internet cache, temporary files, Internet cookies, unused disk space, and a number of other places where data can secretly lurk. It can handle FAT16, FAT32, and NTFS partitions. Erasing files with a high level of security will always be a difficult and time consuming task, and absolute 100% safety cannot be guaranteed. However, Eraser makes the task about as easy as it can be, at a security level that exceeds most conceivable requirements.
If Eraser is overkill for your needs, try UltraShredder. In terms of secure deletion, it's not as comprehensive a solution as Eraser, but it's small, much easier to use, and will work from a USB flash drive.
A somewhat different alternative is Darik's Boot and Nuke (DBAN). It's used to construct a floppy disk or CD that will automatically wipe the hard drives of any PC that's booted from the disk. It's great for bulk disk cleaning of PCs, and is also useful as an emergency tool for quickly removing sensitive information. However, the power of this app makes it a dangerous tool in the hands of beginners.
Product Details
Eraser
Website: http://www.heidi.ie/node/6
Download link: http://www.heidi.ie/node/14
Author: Heidi Computers Ltd.
Version: 5.86a
Date: 01/09/2008
Download file size: 9MB
License: Freeware (GNU)
Operating systems supported: Windows 95/98/Me/NT/2000/20003 Server/XP/Vista/DOS
64 Bit version available: Yes
Portable version available: Unknown
Other languages supported: No
Additional software required: No
UltraShredder
Website: http://www.xtort.net/xtort-software/ultrashredder/
Download link: http://www.xtort.net/xtort-software/ultrashredder/
Author: xtort.net software
Version: 4.5.4
Date: Unknown
Download file size: 213 KB
License: Freeware
Operating systems supported: Windows 95/98/Me/NT/2000/20003 Server/XP/Vista/DOS
64 Bit version available: Unknown
Portable version available: Yes
Other languages supported: No
Additional software required: No
Darik's Boot and Nuke
Website: http://dban.sourceforge.net/
Download link: http://dban.sourceforge.net/
Author: Techway Services, Inc.
Version: 1.07
Date: 01/09/2008
Download file size: 2 MB
License: Free (Open Source)
Operating systems supported: All Windows/Linux
64 Bit version available: Unknown
Portable version available: Unknown
Other languages supported: No
Additional software required: No
This software category is maintained by volunteer editor John Brock.
We’ve all heard the horror stories about someone buying a used hard drive at a flea market or garage sale and then finding tons of personal data left on the drive by the previous owner. Or even worse, people getting their credit trashed by ID thieves that make their living by taking that information and using it to wipe you out financially. “That would never happen to me” you say. “I’ll delete all the files first” or “I’ll re-format the drive before I trade it in or sell it.” Not so fast there Scooter! That data you think you erased is still stored on the drive.
When you delete a file it isn’t really removed from the disk. The operating system (OS) only removes the reference to the file from the file allocation table. This is like going into a book or magazine and removing a chapter reference from the table of contents. The actual chapter is still in the book. The only thing removed was the page number reference in the table of contents. With the file location reference removed the OS now sees that disk space as being available for use. However, the file content remains on the disk until another file is written over it.
Basically the same thing happens when you re-format a hard drive. Most of the data remains; the space on the drive is just made available to be written over.
The DOS and Windows file systems use groups of disk sectors, known as clusters, to store data. These clusters are of a fixed size which is normally determined by the size and number of partitions of the disk volume itself and the file system being used. If the data you’re storing requires less space than a full cluster, the entire cluster is still reserved. For example, you’ve saved a file that required 15.5 clusters of drive space. Because the OS can’t reserve a half cluster, the allocation table had to reserve 16 whole clusters for the file. That remaining half cluster that was not used may still contain data from a previous file. That unused half cluster is known as “slack space”. Data recovery programs can read slack space and retrieve the data stored there. Even worse, let’s say the file system places your 15.5 cluster file over the “unused” area of a deleted file that originally took up 35 clusters. More than half of the previous file would still be retrievable! You could have thousands of clusters on your hard drive (a.k.a free space) that contain data you thought was deleted! Scary thought, huh?
The only true and permanent way to make data irretrievable is to completely and utterly destroy the hard drive. That action is probably a little more severe than you or I need. We really only need to make sure we are protected from data recovery programs and the like. That’s where the programs in this category come into play.
To be as safe as possible, you must overwrite (erase) both slack space and free space. Also, the Windows swap file (a.k.a page file) could contain private data that you wouldn’t want to have fall into the wrong hands.
Eraser will securely erase selected files and folders, or even whole disks, located on your hard drive (it works with any drive, including IDE, SCSI and RAID, and CD-RWs). Eraser can overwrite the data area with your choice of a variety of random data patterns, and can also wipe data in the paging file, Internet cache, temporary files, Internet cookies, unused disk space, and a number of other places where data can secretly lurk. It can handle FAT16, FAT32, and NTFS partitions. Erasing files with a high level of security will always be a difficult and time consuming task, and absolute 100% safety cannot be guaranteed. However, Eraser makes the task about as easy as it can be, at a security level that exceeds most conceivable requirements.
If Eraser is overkill for your needs, try UltraShredder. In terms of secure deletion, it's not as comprehensive a solution as Eraser, but it's small, much easier to use, and will work from a USB flash drive.
A somewhat different alternative is Darik's Boot and Nuke (DBAN). It's used to construct a floppy disk or CD that will automatically wipe the hard drives of any PC that's booted from the disk. It's great for bulk disk cleaning of PCs, and is also useful as an emergency tool for quickly removing sensitive information. However, the power of this app makes it a dangerous tool in the hands of beginners.
Product Details
Eraser
Website: http://www.heidi.ie/node/6
Download link: http://www.heidi.ie/node/14
Author: Heidi Computers Ltd.
Version: 5.86a
Date: 01/09/2008
Download file size: 9MB
License: Freeware (GNU)
Operating systems supported: Windows 95/98/Me/NT/2000/20003 Server/XP/Vista/DOS
64 Bit version available: Yes
Portable version available: Unknown
Other languages supported: No
Additional software required: No
UltraShredder
Website: http://www.xtort.net/xtort-software/ultrashredder/
Download link: http://www.xtort.net/xtort-software/ultrashredder/
Author: xtort.net software
Version: 4.5.4
Date: Unknown
Download file size: 213 KB
License: Freeware
Operating systems supported: Windows 95/98/Me/NT/2000/20003 Server/XP/Vista/DOS
64 Bit version available: Unknown
Portable version available: Yes
Other languages supported: No
Additional software required: No
Darik's Boot and Nuke
Website: http://dban.sourceforge.net/
Download link: http://dban.sourceforge.net/
Author: Techway Services, Inc.
Version: 1.07
Date: 01/09/2008
Download file size: 2 MB
License: Free (Open Source)
Operating systems supported: All Windows/Linux
64 Bit version available: Unknown
Portable version available: Unknown
Other languages supported: No
Additional software required: No
This software category is maintained by volunteer editor John Brock.