Kitz Forum
Chat => Tech Chat => Topic started by: sevenlayermuddle on May 26, 2019, 10:33:31 PM
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An elderly Aunt asked us to dispose of a quite old laptop computer. It had not been used for much, but would have contained the odd email, some banking and hmrc tax stuff, assorted usernames and passwords. I extracted the hard drive, unsrewed the cover to expose the drive’s internals and with a tap from a nearby brick, shattered the glass platter into many pieces. I then reassembled neatly and took it to the public tip.
As I prepared to toss it into the ‘small electrical items’ skip, a member of staff intercepted me. Apparently, they are meant to “destroy” computers, before they are tossed. He poised himself to give it a good battering with a lump hammer, aimed at the keyboard and screen. I declined, said it was not necessary, and tossed it anyway. He seemed surprised but accepted my choice.
Not sure what they hoped to achieve, by battering away at the keyboard and screen. No matter how hard he battered it, the HDD would almost certainly have survived. ???
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Does seem odd, as you say they are unlikely to destroy the hard drive, and are actually making any recycling harder.
I much prefer to recycle, erase the hard drive, or if really concerned remove it and the give the rest away. I have often seen people asking for old computers on free cycle for computer clubs where they teach people how to repair etc. Mind you their motive could be to gain access to the data on unsuspecting peoples drives.
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The PSU had been lost, so I couldn’t even power it up. Else, I might have booted up linux and bzero’d the disk. Or I could have transplanted the disk into another system and bzero’d it there, but that was getting more like hard work.
It was a 12 year old machine, and I had to visit the tip anyway, so I decided to let it go. Glad I didn’t have to watch it getting smashed up with a big hammer though, that would have made me rather sad. Ok, I’d just trashed the disk platter with a brick, but I reassembled it neatly so you’d never have known, and it could land in the skip with a little bit of its dignity remaining. :D
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I have always put hard disks into the stove. If the machine is going to be sold, I put back into it the very same virgin original physical unit that was in it when it arrived, which was removed and packed away when the machine was first delivered, before powering the machine up for the first time with a good empty hard disk of my own.
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As I was reading the thread I just had a thought :idea:
The more ssd's are becoming a thing, what would be the best way to destroy an ssd?
I know we could smash it, but would a powerful magnet to the same job to erase data?
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As I was reading the thread I just had a thought :idea:
The more ssd's are becoming a thing, what would be the best way to destroy an ssd?
I know we could smash it, but would a powerful magnet to the same job to erase data?
Good point.
I believe (may be wrong) that flash storage hardware chips often have a hardware erase cycle, that reliably erases all contents. Trouble is, I don’t know if common OS’s provide a UI to activate it, or what to do if the hardware is already broken and too damaged to erase itself.
Simply overwriting the old data may not actually erase all contents owing to “wear levelling” algorithms used by flash. My own strategy is to avoid putting sensitive data on USB sticks in the first place, and to enable full disk encryption for SSDs.
By encrypting it, I can worry less about whether it is fully deleted, as long the the encryption keys are gone. I have no doubt that powerful nation-state agencies exist, with sinister expertise and tools, that could break the encryption (in my case Apple’s encryption). But I do doubt whether these agencies would go to the trouble and expense of hacking my data, when there are far more rewarding targets - unpopular heads of state, criminals, terrorists, etc. :)
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I know we could smash it, but would a powerful magnet to the same job to erase data?
I would suggest putting the SSD into a glass bowl, along with a small amount of water, and then giving the contents a "blast" at full power in a microwave oven.
Another alternative would be to dangle the SSD from a securely earthed wire in the arc-over range of a Wimshurst machine (https://en.wikipedia.org/wiki/Wimshurst_machine) or a Van de Graaff generator (https://en.wikipedia.org/wiki/Van_de_Graaff_generator). :angel:
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https://en.wikipedia.org/wiki/Trim_(computing)
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FreeCycle is a good way of getting rid of stuff.
You can wipe any disk with DBAN https://dban.org/ to military spec.
As I am still building my own house I have built into it lots of 'Junk' including about 20 hard drives under floors, electronic components, pcb's, books, mags, and built stuff into Box beams, behind partitions etc.
I also include news papers in odd places so people in the future can find them.
There are going to be some surprised people in the future. ;D
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to military spec.
I’m not sure all militaries would agree. I once worked, briefly, on a highly secure project. The development process was closely audited by the customer so when it came time to replace a disk, we had to courier the old drive off for them to ‘sanitise’ to their satisfaction. A few weeks later they returned our disk, with the individual platters packaged separately from the disk, having bad the magnetic coating ground off completely.
I daresay they overwrote the data and degaussed it thoroughly before grinding, but at that time at least (a few decades ago) grinding of platters seemed to be also a necessary final step. :)
Not sure about dban as I can’t open that link (temporary problem, i suspect) but one problem with attempting to trash a disk just by overwriting it is, any data that is in defective and remapped sectors may not be overwritten, but could still contain data that could be recovered. With SSDs there is the additional problem of wear levelling algorithms. Again though, unless you are a seriously wanted criminal, or head of state engaged in international conflict, or a journalist related to such topics, you probably needn’t worry too much.
CarlIT’s ‘trim’ link seems the way to go for SSDs, but not sure if that would work if the drive was already ‘dead’ and unresponsive to the UI, with the possibility of data remaining in the individual chips within?
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Some of these methods seem to be a lot of hassle or take quite some time. Melting the drive to a pool of slag within your stove is cheap and easy. Just add drive next time you are sitting down in the evening with all furries toasting in the warmth.
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Some of these methods seem to be a lot of hassle or take quite some time. Melting the drive to a pool of slag within your stove is cheap and easy. Just add drive next time you are sitting down in the evening with all furries toasting in the warmth.
How does that work..? Does the burning temperature of the stove fuel exceed the melting point of all of the target materials, chip packages, aluminium containers and platters and (for most 2.5” drives) glass platters?
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It has been very very effective in my experience. The results are spectacular when the coal / wood is white hot and a controlled amount of air is being drawn through. The output is just a melted unrecognisable lump whenever I have done this. (Not an open fire.) In any case, I would think that pretty easy to hit the curie temperature of iron at ~1100K if the centre of the fire in an air flow is white hot. A nice mix of wood producing charcoal and coal should reach 1300-1400K roughly according to the source I found when I just looked it up. And definitely will melt aluminium, from personal experience. I have used this method many times.
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Interesting, thanks. ;)
But closest I have to a stove is a charcoal-burning summer BBQ. Might add interesting flavours to the sausages and burgers? ::)
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We have two such stoves. Don’t use the central heating ever as it goes too crazy and I can’t keep the pain under control unless my bedroom is really cold. A big oil-fired Rayburn warms the kitchen and drives the central heating if necessary.
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Some of these methods seem to be a lot of hassle or take quite some time.
My suggestions were to address the query related to the disposal of SSDs . . .
The more ssd's are becoming a thing, what would be the best way to destroy an ssd?
:)
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Re the microwave oven suggestion... how does one know whether it has worked? It may well render the drive unresponsive, but just proves that some damage has been inflicted on some components. Can we be sure that each and every memory chip has been completely destroyed?
To put the above in context, I am comparing the microwave oven and other SSD tactics, with physically shattering a glass platter into many pieces, or grinding aluminium platters, or melting the platters along with individual chips, in Weaver’s stove.
Fascinating debate. :)
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Re the microwave oven suggestion... how does one know whether it has worked?
A good question.
I have no proposition as to how one my determine if the end objective has been achieved. My suggestions for annihilation were purely the result of seeing all the dire electrostatic warnings that the packaging for such devices carry.
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FreeCycle is a good way of getting rid of stuff.
Yes it is, but arranging collection is always a pain, and as we both work I do sometimes wonder who I'm telling I'm not going to be in when I say they can't collect at such and such time.
As I am still building my own house I have built into it lots of 'Junk' including about 20 hard drives under floors, electronic components, pcb's, books, mags, and built stuff into Box beams, behind partitions etc.
I also include news papers in odd places so people in the future can find them.
There are going to be some surprised people in the future. ;D
Yes I did that too when I renovated my first house, various calenders, page 3 of the Sun and I can't remember what else :lol: I certainly wasn't as extreme as you though. How long have you been building your own house?
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Drifting off topic, but I’m authorised to do so as I started the thread...
Re freecycle, I have never used it. But in collaboration with a few others, clearing a deceased’s home, we have used freecycle’s rival, freegle, to good effect. My impression is, freegle has a better reputation these days, UK at least. We had some good successes, with stuff that might have gone to landfill going to genuinely needy people. :)
Main problem seemed to be people who failed to show up at agreed time to collect, which was annoying if I’d made a special trip to meet them. Or people who showed up to collect (say) a large piece of furniture, then left empty-handed as they’d come alone and it was too heavy to move, and/or too big to fit in the tiny car they’d brought. :'(
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Possibly to stop people coming back, aghast, requesting, "Everyone please stop what you're doing. That laptop I threw away had 5,000 bitcoins on it..."
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Secure deletion of SSD, like everything else, is overwriting as much as possible.
I will suggest that people are mindful of how SSDs work: the controller abstracts an awful lot of activities and load leveling makes it tricky to overwrite every cell especially given the overprovisioning of cells.
Run enough iterations of a cell overwrite and you'll get there though recovery is theoretically possible, but running it through a metal shredder then melting the output to ensure any cells that made it through the shredder undamaged are history will definitely work.