On Sun, Aug 28, 2016 at 11:38:12PM -0400, Steve Kinney wrote:
> On 08/28/2016 09:31 PM, Razer wrote:
>
> > If all Hillary's people did was a standard cleaning, that WOULD BE
> > amateur, and the data would be potentially recoverable. Bleachbit CAN do
> > multipass Zero writeovers, but that's not the standard setting.
>
> I have used bleachbit myself from time to time and it seems to perform
> as advertised. However, as far as I know there is no way to reliably
> overwrite files on a mounted journaling file system. Mostly overwrite
> most of the time, yes, but in cases where one must be sure that no data
> survives the process, other measures such as deleting the files that
> have got to go, backing up the remaining non-deleted files and
> overwriting the original file system from end to end would be required.
And for SSDs, assuming also that at least the following are all taken
into account:
- your file system covers the entire disk
- enterprise (greater) and consumer (lesser but still there)
"non-visible parity and failed block replacement" storage areas
- "failed blocks" which have been remapped and are supposedly no longer
readable and writable
- any internal and not visible cache blocks e.g. SSD hardware journal?
or falsh/mram hybrid drives (when available)
- capacitor powered "write the cache to these reserved blocks" blocks
being written in the case of a power outage
And there are probably even more nit picks around...
> All those nit picking little details... ugh. Just encrypt the whole
> drive, and overwrite the key to destroy the data if/as needed. Or
Basically, if "highly funded" adversaries are part of your threat model,
you probably better completely avoid SSDs for all critical data at this
point in time, and use old filesystems with deterministic placement and
"overwritability" capability - like ext2 and fat32. And even then you
better make sure there's no hidden ("switched on by bios") SSD cache,
nor "hardware remapped tracks" going on under the hood.
> better yet, keep the key on a memory stick that can be tossed in a
> volcano or so.
Indeed. And in general assume your phy storage is not deletable, at best
destroyable.
