Buy a computer and before you turn it on, toss it into a woodchipper. Then cremate it and send the ashes forward in time to a sun about to be swallowed by a black hole, just as the universe is collapsing. And then smash it with a hammer.
The surest way to stop others stealing your hard disk data...
- Thread starter Zulu Romeo
- Start date
There are different stages of file deletion:
Recycle bin -- file moved to another folder, possibly compressed. Data is still fully present on the hard disk, and fully indexed in the FAT.
(The FAT is the contents page present on every hard disk, saying where every file is physically located on the disk. It is so that the operating system software knows where to read data on the disk.)
Deleted -- FAT entry disabled so the data isn't indexed, but is all still there on the drive. Undelete can re-enable a file index to 'recover' the data. If more files are written to the drive, the FAT entry and/or the data space may have been overwritten which each obstruct chances of recovery.
Reformat -- Reassigns data blocks and renews the FAT. It overwrites/deletes very little, so most of the original data remains on the disk, although it isn't indexed. Recovering data requires scanning the disk sector by sector, whether the FAT says there is indexed information there or not.
Zero -- Overwrites all data on the disk with binary '0'. Information is generally lost although some magnetic residue may remain, like erasing a audio cassette isn't perfect, as sometimes bits of sound remain but will be at low volume. So naturally, it is possible to get some information back, by listening to that magnetic residue.
Scramble -- Similar to zero, but overwrites data with random 1 and 0. Information is lost within the generated 'noise'. But if the sequence of 1 and zero can be replicated, you know what the residual trace is you are looking for. Often this uses random bits of data from the deleted files, which will not be replicated, so is more secure.
Secure delete -- similar to scramble but is file specific. Data space is overwritten, possible several times so that the original data can't be recovered. There are many residual magnetic traces that all become far to weak to be able to recover. Often this uses random bits of data from the deleted file, which will not be replicated, so is more secure.
Recycle bin -- file moved to another folder, possibly compressed. Data is still fully present on the hard disk, and fully indexed in the FAT.
(The FAT is the contents page present on every hard disk, saying where every file is physically located on the disk. It is so that the operating system software knows where to read data on the disk.)
Deleted -- FAT entry disabled so the data isn't indexed, but is all still there on the drive. Undelete can re-enable a file index to 'recover' the data. If more files are written to the drive, the FAT entry and/or the data space may have been overwritten which each obstruct chances of recovery.
Reformat -- Reassigns data blocks and renews the FAT. It overwrites/deletes very little, so most of the original data remains on the disk, although it isn't indexed. Recovering data requires scanning the disk sector by sector, whether the FAT says there is indexed information there or not.
Zero -- Overwrites all data on the disk with binary '0'. Information is generally lost although some magnetic residue may remain, like erasing a audio cassette isn't perfect, as sometimes bits of sound remain but will be at low volume. So naturally, it is possible to get some information back, by listening to that magnetic residue.
Scramble -- Similar to zero, but overwrites data with random 1 and 0. Information is lost within the generated 'noise'. But if the sequence of 1 and zero can be replicated, you know what the residual trace is you are looking for. Often this uses random bits of data from the deleted files, which will not be replicated, so is more secure.
Secure delete -- similar to scramble but is file specific. Data space is overwritten, possible several times so that the original data can't be recovered. There are many residual magnetic traces that all become far to weak to be able to recover. Often this uses random bits of data from the deleted file, which will not be replicated, so is more secure.
Hammer, drill, and a massive "tool retriever" magnet made for construction sites, I've used them all on harddrives for comps I was trashing. I know a person that swears by the propane torch, melt the fuckers.
Ahhh...good ole' Thermite. The solution to all of life's annoyances.
What the heck are you guys storing on your hard drives that is that confidential? Passwords? change 'em. Home address, phone numbers etc are more at risk from your waste paper basket than someone with the Ultimate High Tech gizmo. Or do you all have vaste collections of illegal porn? Legit porn - who cares if someone finds it. 
When I worked in a secure area, they have to completely dismantle the hard disks and destroy the data platter using a process that I think had magnetic, chemical and physical steps to it. Of course, the rest of us got a lot of really nifty insanely strong magnets out of it. 
When I was in the Navy, the procedure for the proper disposal of hard drives that processed data higher than Unclassified included wiping the drive with Sgt Security followed by either smashing the drive into an unrecognizable lump or even dismantling it and sanding the platters with a heavy grit sandpaper.Smash the hard disk to pieces. With a hammer. From orbit. Just to be sure.
http://news.bbc.co.uk/1/hi/technology/7816446.stm
The study looked to see how easy it was to recover data seemingly deleted from a hard disk. I've heard it is possible to recover such data from a wiped and reformatted hard disk (with some difficulty) but in the context of identity fraud it takes this concept to a whole new level.
Smashing the hard disk, though? Might make reselling a bit of a problem.
Still, good old BBC to popularise the study for general consumption again, eh?
In the UK it's become quite popular recently to dispose of secure media by leaving said drive(s) on a train seat somewhere.
Only with government employees who still haven't discovered silly things like encryption or networks.
I feel the best solution here is to have two drives, and send them with different couriers. Only despatch drive 2 when drive 1 has arrived successfully, and is shown to be untampered.
If it fails to arrive or fails the tamper check, then destroy drive 2 and start again. That's the system I'd institute if I were put in management of transporting secure data.
Drive 1 and 2 are both necessary to read the data, using something like this:
Say you want to record a byte with value 15.
On drive 1 you record 204 (random number)
On drive 2 you record 67. (204 + 67 = 15 modulo 256)
Then the data on one drive is completely meaningless without the other. It isn't even something you could decipher over time as it isn't that kind of encryption.
If it fails to arrive or fails the tamper check, then destroy drive 2 and start again. That's the system I'd institute if I were put in management of transporting secure data.
Drive 1 and 2 are both necessary to read the data, using something like this:
Say you want to record a byte with value 15.
On drive 1 you record 204 (random number)
On drive 2 you record 67. (204 + 67 = 15 modulo 256)
Then the data on one drive is completely meaningless without the other. It isn't even something you could decipher over time as it isn't that kind of encryption.
It's possible they may get that paranoid with the *really* sensitive stuff. Classified material comes at a number of levels of sensitivity, though, and the stuff most cleared personell deal with on a daily basis doesn't require that level of precaution.
At the very least you should encrypt the data no matter what network you're sending it over or what devices you're using to transport it.
Master of Tarquin Hill said:
Why does that sound like the perfect name for a bar for members of this bulletin board?
On topic, I remember a co-worker showing me how he de-magnetized some item at work (by holding a large magnet, slowly rotating it while backing away from the item. Too bad he had magnetic program strips in his chest pocket...they were very nicely de-magnetized.
I lol'ed.
As did I. 
Of course, sending it into the sun poses the additional danger that some criminal mastermind would implant some Kryptonian DNA onto a hard disk in order to create a powerful supervillain powered by electromagnetic rays, with bouffant hair, who can only be defeated by shaking him up and down a lot, placing a huge magnet on top of him, and then striking him with a very big hammer.
I shall call him "Partition Man"!
Touché.And his catchphrase? "Cache me, if you can?"
And I'm caching up with you with the puns.
[She's got you beat for once, ZR, admit it - someone]Actually, I wonder if the techniques described above to delete, encrypt and recover lost data, and also the aforementioned Grabthar's Algorithm of Total Data Security
(as sponsored by Which?) works on solid state hard disk drives?