Tech Support Forum - View Single Post - deleting g-list sectors on hard drives

**raptor_pa** · 12-17-2008, 07:38 AM

OK Let's see here questions in order
1) The FBI ( or more likely CIA and NSA ) and Jesus all have a reasonable shot at recovery.after running killdisk. The question becoms diminishing returns. Reselling information your 10 CC #'s on the open market are worth anywhere from $10 - $100 for the group of 10. Unless they are VERY high limit cards. then they may go for $50.00 each. The type of people who would attempt recovery are not going to use the cards, they would resell the information.

Killdisk does not do the g-list. The G-list is in the service area ( SA) of the drive, an area inaccessible to user apps. The apps don't need to know the bad sectors, the disk firmware needs to know in order to remap that logical block to a spare logical block. Special hardware/software is required to read the g-list area and either read those sectors or blank the g-list so the sectors are available. Cheapest product I've found to do it is about $2000. Keep in mind tho, if the sector went bad, it is probably not readable reliably anyway.

There are other technologies besides Magnetic Imaging Microscopes that can be used to recover data from the platter surface. Spin stands can also be used. Again diminishing returns. If someone is taking the extra effort and time to look this deep, then they are looking for a lot more than your credit card numbers, and have a reasonably good idea what they are looking for and that it exists on the drive.

If security is that much of an issue for you, I would suggest rather than spending all the time looking for software, buy a new or refurbed drive to put into the machine you are selling. Open up your old drive, remove the platters, take some good course sandpaper or a grinder to all the platter surfaces, then place all platters into a tapedup stack in cloth bag, run a drill though the platters a couple of thimes, then take a large hammer and reduce the platters to as small pieces as possible. Alternatively soak platters overnight in some good strong acid :)

Now that being said. 0 Wiping IS acceptable for anything other than DOD classified information. the National Association for Information Destruction certification for digital data destruction does not specify methods of wiping, only the result that they must have. properly applied killdisk, dban. and many other wipe tools will pass the testing easily. And is probably more than sufficient for your uses.

12-17-2008, 07:38 AM	#2 (permalink)
raptor_pa Mod Hardware Team Join Date: Dec 2008 Location: Central PA Posts: 4,903 OS: XP	Re: deleting g-list sectors on hard drives OK Let's see here questions in order 1) The FBI ( or more likely CIA and NSA ) and Jesus all have a reasonable shot at recovery.after running killdisk. The question becoms diminishing returns. Reselling information your 10 CC #'s on the open market are worth anywhere from $10 - $100 for the group of 10. Unless they are VERY high limit cards. then they may go for $50.00 each. The type of people who would attempt recovery are not going to use the cards, they would resell the information. Killdisk does not do the g-list. The G-list is in the service area ( SA) of the drive, an area inaccessible to user apps. The apps don't need to know the bad sectors, the disk firmware needs to know in order to remap that logical block to a spare logical block. Special hardware/software is required to read the g-list area and either read those sectors or blank the g-list so the sectors are available. Cheapest product I've found to do it is about $2000. Keep in mind tho, if the sector went bad, it is probably not readable reliably anyway. There are other technologies besides Magnetic Imaging Microscopes that can be used to recover data from the platter surface. Spin stands can also be used. Again diminishing returns. If someone is taking the extra effort and time to look this deep, then they are looking for a lot more than your credit card numbers, and have a reasonably good idea what they are looking for and that it exists on the drive. If security is that much of an issue for you, I would suggest rather than spending all the time looking for software, buy a new or refurbed drive to put into the machine you are selling. Open up your old drive, remove the platters, take some good course sandpaper or a grinder to all the platter surfaces, then place all platters into a tapedup stack in cloth bag, run a drill though the platters a couple of thimes, then take a large hammer and reduce the platters to as small pieces as possible. Alternatively soak platters overnight in some good strong acid :) Now that being said. 0 Wiping IS acceptable for anything other than DOD classified information. the National Association for Information Destruction certification for digital data destruction does not specify methods of wiping, only the result that they must have. properly applied killdisk, dban. and many other wipe tools will pass the testing easily. And is probably more than sufficient for your uses.