The art of wrecking an hard disk drive.

Any creative ideas on how to wreck / secure clean an hard disk drive before disposal?

dd if=/dev/zero of=/dev/disk_drive?
shred -n whatever -z /dev/disk_drive?
Magnet? (false sense of security)
Fire?
Hammer?
Acid?

Post your thoughts.

IMO dd is enough.

  • nilesh

There are companies out there that physically shred the disk drives - think of a paper shredder on steroids. And, they can provide a statement of physical destruction. Depending on the type and nature of information, this may be the best route to take - especially if you never want to hear your own or company name in the paper for "found data". I have used these services in prior jobs - when the data necessitated it.

Next best would be a combination of program destruction - as already discussed, and some physical destruction. It would at least deter the casual snoop to data.

The prevailing issue needs to be the kind of information and the need for protection. Obviously, credit card transactions or individual finance/health records would be more important than 5-year-old inventory logs from a supplier; and thus would need "better" destruction.

-- since you do not have a protocol established for disk 'elimination' find a company in the same business as yours and determine what they deem is appropriate. For example, we are bound under US federal law: Oxley-Sarbanes - so called SOX. We use a company that literally shreds disks. It may be overkill, but apparently our auditors don't think so.

some companies have a nice square concrete box in the smoking lot, and they add a new layer of concrete with the hdd inside

you could also, open the disc, and use some kind of powertool

or you could put that hd in another box, and run dd over and over again for some time,
make it random, no always 0 over 0

you can recover hdd info from a hd if it was deleted once, or twice. i have read about recoverng info after eleven passes., but im sure that if they are capable of using that tech, they could easily bribe another employe for the same info.
so just use dd a few times, and one or two hits with a hammer.
hammers always fix things

as a side note, do you know the guy from "will it blend?" ?

Take it apart. You will get a few jumpers, quite a few screws, and some really cool and powerful magnets. If rubbing those magnets on the platters doesn't assure you, scratch the platters up or bend them.

Careful though, these are powerful magnets!

This is actually my only source for jumpers. Not sure where else to get them...

Some people think the extreme methods are overkill, but be careful. Data recovery services are capable of pretty amazing things. Beyond the typical melted in a fire/accidentally demagnetized/encrypted and forgot password stuff they can recover data from some really weirdly damaged disks.

I found an email I remembered forwarding to some friends a year ago from a cnet news.com article on the strangest jobs Kroll Ontrack had this past year. In all these cases they recovered the data.

� In the middle of an argument, a businessman threw a USB stick at his partner, with the device ending up in several pieces on the floor. Unfortunately it contained valuable company plans.

� A scientist was fed up with his hard drive squeaking, so he drilled a hole through the casing and poured in oil, stopping both the squeaking and the hard drive.

� To test the functionality of a parachute, a camera was dropped
from a plane. The parachute failed and the camera shattered into several pieces, but the device's memory stick was reassembled and the footage was recovered.

� After discovering ants had taken up residence in his external
hard drive, a photographer took the cover off and sprayed the interior
with insect repellent. The ants were killed off and the data was eventually recovered.

A colleague has friends in the data recovery business. They recommended 25 runs with shred in order to make it reasonably hard for them to recover the data; ten runs would be something they could routinely cope with. Still, modern hardware maps out bad sectors on the fly, and you then can't shred those mapped-out sectors, so their ultimate recommendation is physical destruction. Strong magnets I would have thought would be a good approximation, but apparently redoubtable thinks otherwise?

era I'm not quite sure about the magnets, I just heard that it was possible to predict the modifications and reverse them. But this is not even close to my areas of expertise so I can't be sure. I was hopping someone would also explain that when I opened the thread.

That's a good point. The hard disk has some sectors reserved to replace others when they become unusable and although those sectors (being bad and all) cannot be read from or written to by the kernel, they can still be read using special microscopes and some information can still be recovered.

Watch it Shred!: Hard Drives :wink:

A drill is a little neater than the hammer