Tuesday, 30 December 2008

Destroying old hard drives

This is a simple, cheap method for destroying old hard drives, making the data unrecoverable against casual attackers and identity fraudsters (although probably not some hypothetical government agency with multi-million dollar resources).

For this you will need a stack of old hard drives:

An electric drill with a twist drill bit (suitable for going through metal), and most importantly some eye protection:

Line up the hard drives against the wall and drill straight through them. I didn't show it in this picture, but in fact I drilled through from the other (PCB) side to ensure that I went through the PCB but didn't go through any components that might explode:

Sunlight where there's not supposed to be sunlight!

For a few of the drives, mainly older ones, I couldn't get all the way through, but I got through to the platters, which is the important part:

Now you can see why eye protection is not optional. This old IBM SCSI-LVD drive had glass platters which shattered into tiny, sharp shards of metal-plated glass when the drill went through:

For extra assurance, I will soak the drives in a bucket of water for a few days before disposing of them:


Michael said...

I usually line them up and shoot them several times with a rifle or pistol.

Smooge said...

Does soaking in water do anything? I would think an acid or bleach would be a better mix?

Richard Jones said...

Michael: Outside the US, it's very hard to get hold of a rifle or pistol which is capable of damaging a hard drive. (And that's a good thing!) The penalty for owning and discharging a pistol here in the UK is many years in prison.

Smooge: That's a very good question.

I think that the water may further damage the electronics (although I never myself have understood the method by which low voltage electronics is damaged by water), and also the water should cause the internals to begin rusting more quickly after they have been thrown away.

Bleach is a good idea. Bleach has the advantage that it is also cheap (not as cheap as water though!)

Acids are slightly more tricky to get hold of, although I guess you can buy vinegar and some other acids cheaply in the local supermarket.

Perhaps water + bleach or water + vinegar would be a better final step?

Dharampal said...

I was just wondering, what's wrong with just throwing it hard against a rock?
I'm sure that'd shatter the platters :D

Richard Jones said...

Dharampal: A rock might shatter glass platters, but out of the 9 drives, only one had glass platters! (AFAICT)

Another commenter suggested a sledgehammer.

This method has the advantage that it damages the PCB beyond usability, damages the platters (perhaps shattering them), and fills the interior of the drive with metal shavings. So you'd need to replace the electronics, and there is no chance the original head/drive assembly can be used because the head will crash immediately if you tried to spin it up.

It takes about 45 seconds / drive to drill through each unit, so it's pretty quick too.

ivazqueznet said...

Water won't do. Get a couple of liters (quarts?) of hydrofluoric acid. But be careful as HELL around it. It eats through ANYTHING except a few plastics.

Richard Jones said...

Hmmm maybe the purchase of hydrofluoric acid is tricky at the local Sainsburys?

moozaad said...

a couple of cans of coca cola should do it (3 ph) - leave to soak overnight and voilĂ ; a sugary corroded mess :)