How to erase data securely in case of selling laptop?

I've heard that simply deleting the data isn't enough. Is this true?

 

Yes it's true.

There is a decent guide here:
How to Securely Delete Data from Hard Drives - eSecurity Planet

 

For an SSD, you should do a secure erase. For a mechanical drive, simply overwriting the entirety of gthe drive with 1, 0, pi, or anything else (there are plenty of drive wipe prpgrams that will do this) will work.

Sent from my Tricorder using Tapatalk

 

use moral hazard's link. Dban will do the job well.
took me 3 hours to do a three pass on a 80gb hard drive.

 

I HIGHLY recommend Gparted for secure erases. It's small and lightweight, and easy to burn the iso to disc. GParted -- About
The command I always use in the terminal, is:

Code:

sudo dd if=/dev/zero of=/dev/sda bs=256k

assuming your HDD is at /dev/sda (which it should be if it's the only one installed). That will zero it out once. I would do it 3 times atleast if you're selling it.

I've been using it for a long time now, and never had any problems with it.

 

Just three passes? I perform a Gutman wipe (35 passes).

 

That's pretty extreme. Even the DoD only does 7 passes.

 

That' because delete doesn't erase it merely renders that space as usable.

 

Data can always be recovered. My advice is just buy a new HDD for it and install it if your worried about them getting personal information.

 

3 was enough for me. Gutman is the best but it can take days especially with much larger hard drives now a days. mine was a 80gb and only showed 74gb and that took just over 3 hours so ill let you do the maths using the 35 pass

i think Dban has about 6 choices and the 3 pass was a DoD approved.

 

I know that Gutman takes forever, but still...

 

Any way to write data over the existing data is fine. Even selecting to do a full format through Windows will get the job done as it writes 0's to the entire drive in one pass.

 

XP does not do this, only Vista and W7

ecksodia, see this post for other methods. No need for gutman erase, one overwrite will make it unrecoverable by anyone.

windows xp - What's the best way to completely remove everything from a computer, without re-installing? - Super User

 

Incorrect. You can do it through the command prompt by booting up to a windows install disc, but by default just formatting the drive in windows (all versions) just erases file indexes, but the files are still there. It does NOT write zeros to the hdd.

 

"By default in Windows Vista, the format command writes zeros to the whole disk when a full format is performed. "

this did not change for W7 or 8, and does not have to be done from a boot disk, by default a full format writes 0's.

Change in the behavior of the format command in Windows Vista

 

A full format. I see. That's something new then that I didn't know about. A little late to find this out now though.

 

So are you saying that even if it's reformatted or fresh clean installed, the old files are still in there and can be recovered by fbi or the cia or even anyone?

 

Use Microsoft's tiny sdelete program to zero out empty space: SDelete

 

No. He means if you just delete whatever files from the trashcan. Also if you do a clean install without doing a full format first, there is still data that has not been overwritten.

 

Even a formatted drive can have data recovered via data carving. It takes a long time, costs $$$ but data recovery specialists can do it.

Gutman 7 pass wipe is minimum DoD standard, 35 pass is kinda overkill IMO and will take forever. Just boot from a Darik's Boot and Nuke disc and nuke it.

 

You should specify "quick" format as opposed to a "full" format where the data is overwritten.

Anything more than just a full format is overkill unless you have nuclear launch codes or the plans for the Death Star on your computer. Once the drive has written a 1 or 0 to the disk, in that same spot it can only ever read the 1 or 0 it last wrote. The only way to recover any part of such data would be to remove the platters from the drive and have the CIA / NSA play with them forever.

 

ditto dariks. does a good enough job. if you want to get fancy and the hard drive itself supports, use "Secure Delete" tool in UBCD.
by all means, don't simply reformat - its so easy to get data off a reformatted drive that a 10 year old could do it accidently...

 

For all intents and purposes, it is impossible to get data off a reformatted hard drive. But this means don't click on any "quick" format feature that doesn't actually reformat the drive.

 

If you're seriously concerned, buy a new or used hard drive for the notebook you're selling or sell it without one and destroy the original.

If you really feel you need to do a 35 pass wipe (3 should be MORE than sufficient) then better to just take a sledge hammer and magnets and fire to the platters if you're that paranoid.

If you do wipe, filling with random data is the best way IMHO followed by all 0's or 1's.

It takes expensive equipment to recover data from a multiple wiped (as in 2-3) hard drive, and even more difficult from an SSD. So unless you've got account numbers with millions to billions of dollars stored, then nobody is going to do more than a rudimentary check, and even that is highly unlikely.