[LINK] Self-erasing flash drives destroy court evidence

[Bernard Robertson-Dunn]

On 3/03/2011 10:15 AM, Roger Clarke wrote:
> At 9:55 +1100 3/3/11, Bernard Robertson-Dunn wrote:
>> Self-erasing flash drives destroy court evidence
>> 'Golden age' of forensics coming to close
>> By Dan Goodin in San Francisco
>> Posted in ID, 1st March 2011
>> The Register
>> http://www.theregister.co.uk/2011/03/01/self_destructing_flash_drives/
> ...
>> Data stored [in solid-state memory] is [able to be] permanently erased ...
> So, normal service is resumed.
>
> Recoverability of nominally deleted data was an incidental feature of
> magnetic recording media, different from rocks, vellum (remember the
> palimpsest!) and paper.
>
> The feature will fade away as magnetic media fades away.
>
> To co-opt one of the great advertising lines:
>
>          'What part of 'delete' don't you understand?'.

There seem to be two issues here (I think)

1. When you delete a file on a disk, only the directory entry gets 
erased. The data remains, unless overwritten. On an SSD, the deleted 
data disappears in a garbage collect manner, even though it hasn't been 
overwritten.

2. I was told some years ago by a techo at an agency that does spooky 
things, that even if you overwrite data on a disk, there is evidence of 
up to 7 previous versions of the data. With an SSD there is no evidence 
of even the previous version. I don't know if this is still true with 
today's higher density storage devices.

I'm not sure that the article refers only to the first issue or both.

-- 

Regards
brd

Bernard Robertson-Dunn
Canberra Australia
email:	 brd at iimetro.com.au
website: www.drbrd.com