Is Zero a Hero?
Last week I decommissioned Dogger (aka see-thru-pee-o) after a good six year innings as my main PC. It cost me a lot to build, but was worth it for it's longevity. At the time, adding 1GB of RAM seemed OTT, whereas now it's the norm.
While the 21" Sony monitor remains in service the rest of it has been dismantled and given away. Apart from the hard drive that is. In this age of paranoia I decided not to take any risks and took a lump hammer to it. Nobody will be steeling my identity from that disk!
Is this a little drastic though? When I sold my Mac Mini recently I used Disk Utility to "zero" the hard drive. As I understand it this over-writes ever single bit of data stored on the disk and removes the risk of it being recovered. Is this the case though?
When the Freecycle scrounger called the other day I gave him my sister-in-law's (bloody hell, I've never realised I've got one of them!) PC, which I'd also zeroed using a download from Seagate. That PC had stored all their business accounts and whatnot on it. Please, somebody put my mind at rest and tell me that zeroing really does make it impossible to recover data.
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Jake,
It depends on what level of paranoia you want. There are verying levels of "zeroing" a drive. You can write over the bits once (any software recovery process can get this data back) or multiple times. There are programs which will even do up to 37 writes (very old Department of Defense recommendation). At this level of zeroing, you'd need a clean room, and some very expensive equipment, but it's still possible (although I suspect your lurker probably hasn't got this ;) ).
As an example, I had a drive which I reformatted three times over the course of it's life (4 years). I accidently lost a file on it, and ran some recovery software, which not only found the current partition, but the previous ones as well!
Ultimately, you only really get rid of the info if you use your "lump hammer approach".
More info here:
{Link}
As Steve says, it depends on your level of Paranoia. There are companies out there that specialise in hard disk recovery. I had to use one about 8 years ago, when my disk crashed and I founf out that my backups were also not recoverable. The Lump Hammer approach is still not foolproof as platters can still be mounted and read by recovery companies.
Even if you do give away your machines {Link} it depends on the trustworthness of who you give/sell them to. As Domino developers/admins there are times when you have access to some very sensitive corporate and personal information. Speaking for myself, I have a very high degree of ethics and would *NEVER* divulge any such information. Heck, I even have access to around 8,000 credit card records {Link} but do you see me sitting on a beach in the Bamahas? No.
It all comes down to "who do you trust?"
Zerong is just fine, though its better if you un it through a couple of times, as data recovery firms can extract magnetic data from previous images on a disk, though you would have to be desperate and well heeled.
Reformatting is ineffective as this just rewrite the fat and the original files are left in place, just they have no pointer in the fat.
I've come to the conclusion that I will never give away a computer with a hard drive in it. In fact I just dumped a few old machines a few weeks ago and pulled the disks.
Don't know if this works or not, but I've heard baking a hard drive (yes, baking in an an oven) @ about 400F for 20 minutes or so takes care of the data permanently, as well as the disk.
HackedGadgets.com has a story somwhere in the past few months about a guy in Las Vegas who specializes in Hard disk DEstruction. He takes a blow torch to the platter itself until the surface is completely marred and a large protion of the metal platter is liquified. He seems to think this is a sufficient means of securing your throwaways.
Personally, I like the flaming battery approach Dell has built into their laptops as a security measure. Burning Lithium seems to burn a hole through a laptop just fine. I imagine a HD wouldn't put up much resistance to this kind of incindiary security device. Next thing you know everyone will have combustible battery security devices in their laptops. oh - hang on a minute...
Being extremely impressed by Jerry's ability (and braveness) to publically reveal what Dell really had in mind with their high-security notebooks, I would personally opt for (what I think is) the golden mean.
I would not want to rely on simply zeroing a disk. As precisely as HDD heads have to be positioned, they are still mechanically moved parts and as such there is a certain tolerance in their movement. Also the depth of magnetization might leave room for recovering previously stored data. So, overwriting data multiple times is definitely a good idea, and so is using (pseudo-)random data patterns instead of just zeros.
A very handy and extremely easy to use tool for securely (yes, I would really call it secure ...) erasing hard disk can be had for free at sourceforge: Darik's Boot and Nuke. Just boot DBaN from floppy or CD, make your choice between a number of algorithms (including American and Canadian official standards) and off you go. Depending on the algorithm you selected and the size and speed of your drive, the process might take from one to a couple of hours, but since it runs all by itself, this costs you nothing apart from patience and electricity.
{Link}
I forgot to add: It makes for a perfect virus cleaner as well ... ;-)
Thanks for reminding me about my old drives kicking around. I have my Big Green Egg BBQ (the best) {Link} and I can get that up to 1100 F. throw that drive on an iron skillet and say goodbye.
hi jake and fellow feedbackers, very interesting topic just thought i would add my .5 pence worth..in that apparently over 65% of hard drives sold on ebay still contain data ...!
small hole drilled and acid injection works well in conjunction with an angle grinder.
I would not worry Jake, data is only useful in context, just ensure all public account passwords are changed just in case. However, i cannot imagine anyone wasting time and money recovering data from your sister-in-laws hard drive, unless of course it is well known that your sister-in-law is working on a top secret military project, and if this was the case then the hard drive would be in a laptop secured in the backseat of a car in plane view waiting to be stolen, this is the UK's MOD's data security policy which has been used for years and is still apparently working well as the liberated laptop's data cannot be read by anyone as it has been written over with splinter cell, tomb raider and donkey kong...!
Jake,
you can try this tool :
{Link}
It is a very secure way to destroy all data on the disk (no recovery possible).
Chances are you're ok as it would take a fair amount of effort to get it all back. There's no limit to people's paranoia though. I worked for a large bank a while ago - when they ditched old servers they kept the hard drives and memory and had them physically destroyed by a specialist firm. I understand the hard drives but the memory chips? Seems a little ott to me.
This should do the trick ...
{Link}
But if you're really, really, really paranoid, you may need to get your hands on one of these babies instead...
{Link}
Everytime I've had to have a disk recovered using a disk recovery company it was VERY expensive, especially for an individual. Surely this would be a pretty good deterrent for Joe Schmoe to not spend the big bucks for something that might not be a sure thing?
Keith
I always choose Data Recovery Wizard, made by EASEUS.com.
See more from: {Link}
Well i have a brother who used to work in a company where they got PC's and Servers from several German banks to kill them. They used a 8 time random bit by bit overwriting program to destroy everything that was on those disks.
Simply deleting the files and formatting a harddisk does not do the trick. But rewriting everything is a very secure option. They gave one of those disks to a specialist in disk recovery but those guys could not do anything to recover the data.
in linux
dd if=/dev/urandom of=/dev/hdc;
dd if=/dev/null of=/dev/hdc;
dd if=/dev/hda of=/dev/hdc;
then reformat it.
if they recover it will be /dev/hda data.
Since your original naming you have added /replaced a few machines how about an update on there names.