scrapping a computer - what do I need to do to make it safe?

emmaroids

whats wrong with just chucking it in the local skip?

Cricri

spurs1234 wrote: »

Oh he's right it is very very easy unless the disks are smashed

Sigh.

From Wikipedia about DBAN:

"The program is designed to securely wipe a hard disk until data is no longer recoverable, by overwriting the data with random numbers generated by Mersenne twister (a PRNG)."

Of course, if you simply format the drive with Windows, or even worse, quick format it, then yes it is recoverable.

Emmaroids: well, in today society of cuonsumption, it seems totally fine indeed. I just find it a shame that landfill get filled with working equipment. But then it's just me. No, I'm not a Greenpeace member

albertross_2

emmaroids wrote: »

whats wrong with just chucking it in the local skip?

http://blog.btbroadbandoffice.com/archive/internet-security/sensitive-information-still-on.php

Cricri

Well, I was more talking about the ecological impact, but that's another good point though

Funnily enough, from the article:
"Deleting files or quick-formatting the drive is not secure enough as it's easy for lost files to be 'undeleted' or recovered. It is possible to securely wipe the contents of a hard drive using a free software programme such as Darik's Boot and Nuke from Sourceforge.net."

I'm just pointing it out before someone says again "No, the data can be easily recovered". Good news is, I'm done with this argument, I'm tired of that now.

streather

simplest method is hammer + hard drive


funny thing is i've seen the industrial methods of destroying hard drives and all they did was stick it in a vice and had a big machine drive a point straight through the middle

bluseychris

Cricri wrote: »

Sigh.

From Wikipedia about DBAN:

"The program is designed to securely wipe a hard disk until data is no longer recoverable, by overwriting the data with random numbers generated by Mersenne twister (a PRNG)."

That's (pretty much) the DOD disk method I already mentioned.

spurs1234

Sigh.

From Wikipedia about DBAN:

"The program is designed to securely wipe a hard disk until data is no longer recoverable, by overwriting the data with random numbers generated by Mersenne twister (a PRNG)."

Of course, if you simply format the drive with Windows, or even worse, quick format it, then yes it is recoverable.

Emmaroids: well, in today society of cuonsumption, it seems totally fine indeed. I just find it a shame that landfill get filled with working equipment. But then it's just me. No, I'm not a Greenpeace member

Hmm as stated before software wipe's even if they are binary wipe's (which is what you've read) will not stop a drive being recovered if someone really wanted to !

But i suppose its a case of believing what you have read on the internet and not having an experienced anything first hand, obviously people believe the internet. good luck to you with that :rolleyes:

MORPH3US

Right, question / thought:

If deleting a file doesn't really delete it, it just "loses" it which can then later be recovered by searching the HD for stuff....

Why not just delete all the files you want rid of, then save a zillion copies of a random picture found on the net (for e.g) to fill the HD. Then it willhave over written all the (deleted) "lost" files.....

M

Cricri

Whatever.

Ok, I'll admit, I've been lying all along. You can VERY EASILY recover a hard drive after a WIPE.

Hard drives like floppies are magnetic media, and thus store analogical information (i.e. a 1 will never be exactly 1 and a 0 never exactly a 0, but say 0.83 and 0.12 from a drive head point of view).
Sure, if you change a 1 to a 0 ONCE, this 0 will have a value "a bit higher" than a 0 wrote back to 0. In which case, yes, you can estimate what the previous value was.
However, if you are going to change this value to 0 or 1 randomly and do that 30 times in a row, chances that someone we'll actually be able to figure out that this bit has been purposedly overwritten say 30 times, and that 30 times ago this bit was exactly 0 or 1 is very very very unlikely. Nevermind doing that accurately on several gigabytes of data. But of course, as someone pointed out, you have to know what you are talking about.

bluseychris: yes you did, I don't argue with that. I specifically said that DBAN indeed uses something similar to DoD/MoD standards in a previous post.

Oh, wait, I forgot what I posted for, I was admitting I'm lying. So to summarise, yes you can very easily know what was the value of a bit even after it was overwritten with 0/1 many times in a row (i.e. using a crystal ball, drawing tarot cards, etc), and I was unaware that DBAN was meeting criteria such as DoD standards despite specifically saying so earlier.

I think a lot of people do not grasp the difference between a simple file delete (which in many cases only deletes the file data from the file system, while the data itself is untouched and therefore completely recoverable), a proper file delete (which overwrites BOTH file system information and file contents once), and a secure wipe (which overwrites both file system information and file contents many times times in a row until it cannot be retrieved because the original magnetic state of the corresponding bits have been purposedly obfuscated).

Sorry for lying, do not ever wipe your drive, it won't work. Don't burn it either, some sorcerers can read in ashes. Don't machine it either, there are many swarf reading sorcerers as well.

wakandem

just format the drive & reinstall the os. If you are worried then use one of the progs mentioned above but at the end of the day no one is interested what was on the drive even freecyclers. The issue came to a head when businesses were chucking out old pc's and they were ending up in places like Nigeria where they were read, but as most of the drives had not even been deleted let alone formatted it wasn't that difficult to get the info off them.