hacked by the (alleged) `amazon-security' scammers

[Ralf Mardorf]

On Sun, 7 Nov 2021 12:40:47 -0500, Slade Watkins wrote:
>On Sun, Nov 7, 2021 at 11:01 AM Ralf Mardorf wrote:
>> If you should consider to use shred...
>>
>> $ apropos shred
>> shred (1)            - overwrite a file to hide its contents, and
>> optionally delete it
>>
>> ...overwriting items just one time is enough. It makes not much
>> sense to overwrite items several times.  
>
>I'd like to second this. If you want to do it twice to make sure,
>that's fine, but anything more than 1 or 2 times is enough.


Hi,

IIRC it's not recommended to use 7 or 8 passes anymore and mentioned
that 1 pass usually is enough. IIRC security guidelines still recommend
3 passes.

"[snip]
Please note that shred relies on a crucial assumption: that the file
system and hardware overwrite data in place. Although this is common
and is the traditional way to do things, but many modern file system
designs do not satisfy this assumption. Exceptions include:
[snip]
Generally speaking, it is more reliable to shred a device than a file,
since this bypasses file system design issues mentioned above. However,
devices are also problematic for shredding, for reasons such as the
following:

    Solid-state storage devices (SSDs) typically do wear leveling to
    prolong service life, and this means writes are distributed to
    other blocks by the hardware, so “overwritten” data blocks are still
    present in the underlying device.
    Most storage devices map out bad blocks invisibly to the
    application; if the bad blocks contain sensitive data, shred won’t
    be able to destroy it.
[snip]
    The shred command can use many overwrite passes, with data patterns
    chosen to maximize the damage they do to the old data. By default
    the patterns are designed for best effect on hard drives using
    now-obsolete technology; for newer devices, a single pass should
    suffice.
[snip]" -
https://www.gnu.org/software/coreutils/manual/html_node/shred-invocation.html

Regards,
Ralf