Ssd can be permantly erased or not?

[alohascott]

Aloha
I have bought a few ssd and used them a bit and then I sold them.

now my friend tells me that they can not be erased beyond recovery.

when I wipe mine using secure erase it only takes a minute or two.

am i doing this wrong?

 

[sminlal]

Secure erase resets the drive's mapping tables so that the data inside will be re-used. Once it's done any request to read the unmapped data will return 0's. Over time the drive will erase the cells for reuse, although this may not occur right way.

So although the data itself may not actually overwritten right away, there's no way to get at it short of cooking up and loading special firmware into the drive that can dump the raw contents of all the cells. And since the data is scattered randomly throughout the cells you'd also need some analysis to try to piece it all back together again.

In short, you don't really need to worry about the data unless you think someone would have an awfully strong motivation for trying to recover it.

 

[alohascott]

what about doing some sort of large file transfer over and over again to wipe the contents?

 

[sminlal]

You could do that, and it really would overwrite the data, but to be safe you'd basically have to completely fill the drive up with new data. You'd still want to do a data security erase at the end of it all to reset the mapping pointers and restore write performance to it's original condition.

Personally, I don't think it's worth it. Don't underestimate how difficult it is to extract data from an SSD that's had a data security erase operation done on it. It's not something that could be done by 99.999% of the people and the other .001% probably couldn't be bothered.

 

[craighay]

You could use a large hammer to be sure....

 

[alohascott]

I think an easy way to do this is to move a big zip file onto the drive or a few of them and let them unzip to the drive. At some point it will get full. I don't think it would be that hard.

 

[alohascott]

or tape it to the train tracks

 

[MarkG]

AFAIR the new Intel SSDs use an internal encryption key to encrypt the data, so you can 'securely erase' it just by telling it to generate a new key.

 

[alohascott]

Which ones are those?

 

[MarkG]

I'm pretty sure my Intel 320 does (I think it's mentioned in the docs on Intel's web site). But I'd be wary of buying one until Intel have proven they've fixed the bug where it wipes itself and claims to be an 8MB drive even when you don't ask it to.

 

[alohascott]

just a minute
your intel drive wiped itself beyond recovery then downgraded itself to an 8MB not GB drive.

man, I would be getting upset a bit about that.

anyway

is there any advantage to secure wiping the drive more then once.

from what i understand secure wipe is basically applying higher then normal voltages to the drive for a brief period. it usually takes less then 15 seconds for my 60gb drives.

so is there any reason why I should not just do two or three secure wipes in a row?

is there any possible improvement in wiping the data doing this?

 

[cadder]

I think an easy way to do this is to move a big zip file onto the drive or a few of them and let them unzip to the drive. At some point it will get full. I don't think it would be that hard.

I have wondered how effective this would be. I have followed this procedure with mechanical hard drives.

I'm suspicious that an SSD has some additional memory that it doesn't let you use that it uses for its internal housekeeping, and you cannot get to this memory. But a sufficiently motivated government organization probably could get to it, and you would have no idea if this memory held sensitive information or not. I don't know if any of this is true or not. I don't think I've ever stored anything on a hard drive that anyone but a business competitor would want anyway.

 

[alohascott]

i did it also a couple of times like i said. i had some big 10gb files that i had zipped and i let 6 of them run until the drive was so very very full. with just a few mb like 4 or 6 mb left free.
i think it would be hard to get anything from that tiny amount of space.

 

[alohascott]

nice to know someone actually thinks in similar ways to myself

 

[luke662]

you could download a program called CCleaner. It has an option that allows you to right 0 Values to all blank space on drives. Though this i think is pointless as sminlal couldn't be more right, the effort it would take would far out way the rewards unless you where a high up government official with the truth behind some pretty heavy stuff on your drives...If you are, then dude stop being cheap, you get paid enough. hammer time it and get another.

 

[cadder]

I was reading an old article on Toms last night about the Intel 320. It said that the SSD contains extra space that it uses for garbage collection and so forth. This extra space you can't get to by writing "0" values, but the drive uses it when it wants to. This extra space could contain any of your data and you could not erase it. If a person modified the firmware then they could have access to this space and could read it. Of course Intel could provide a utility to completely erase everything, if they wanted to.

 

[MarkG]

If a person modified the firmware then they could have access to this space and could read it. Of course Intel could provide a utility to completely erase everything, if they wanted to.

So long as you wiped the encryption key, that doesn't matter, because the data they read will be encrypted with the old key and hence pretty much impossible (most likely actually impossible if the key is truly random) to recover.

 

[alohascott]

I have and use ccleaner (crap cleaner ha) and not sure if i would use it for this purpose.

I think secure erase leaves the drive in a better state for future use.

 

[alohascott]

Best answer selected by alohascott.

 

[Mousemonkey]

This topic has been closed by Mousemonkey