Wiping a USB drive.

Does formatting several times effectively wipe a small thunb drive?

On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

On 05.06.20 0:03, Peter Jason wrote:
On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

You dont need a wipe app.
Just empty the stick.
then write some useless file(s) until the stick is full.

In article ,
lid says...

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.

A Quick format does nospam says, but a full format (takes a LONG time)
does overwrite the data. It won't pass an NSA test - the data might be
recoverable, but not with "ordinary" means.

Peter Jason wrote:
does DOS have a wipe app?

A useful utility disk to have around for DOS tools is the 'original'
make-up of Hiren's boot CD, now at 15.2. It has several 'erasers' for
DOS, DiskWipe, HDD Eraser, & Shredder.

If you don't want the whole bootable CD/USB toolkit, you can dl
individual files linked from the site/page, including the erasers.

https://www.hiren.info/pages/bootcd All in One Bootable CD which has
all these utilities

Later Hiren's did a Win PE type disk. https://www.hirensbootcd.org/
Hiren’s BootCD PE

--
Mike Easter

On 2020-06-04 5:11 p.m., Sjouke Burry wrote:
On 05.06.20 0:03, Peter Jason wrote:
On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

You dont need a wipe app.
Just empty the stick.
then write some useless file(s) until the stick is full.

That's doing it the hard way, Like having Sex standing up in a canoe. :-)

Rene

Peter Jason wrote:
Does formatting several times effectively wipe a small thunb drive?

http://www.chrysocome.net/downloads/dd-0.6beta3.zip

(Instructions)

http://www.chrysocome.net/dd

Administrator Command Prompt.

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1M count=12345

Flash devices should have storage related to power-of-two numbers.
The "1M" is 1 megabyte or 1048576 bytes.

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1048576 count=12345

Using dd --list you can get a summary of the device sizes.

Divide the device size by 1048576, and get a number to substitute for
the 12345 field in the example.

This utility wipes every sector, as long as the "offset" selected is
Partition0. Partition0 starts at Sector 0 of the device. This
allows not only removing all private data in the partitions,
but also wipes the partition table, GRUB area, all areas get wiped.

Note that Disk Management lists the disks in the same order,
as the "HarddiskX" field in the dd --list output. Be *especially careful*
to not erase the *wrong* Harddisk0 or Harddisk1 or whatever. I
expect you could even erase portions of C: if you were that
careless. Like sawing off the branch you're standing on. The
computer case LED should not flash, if you're erasing a
USB stick. The USB stick LED should flash instead, as the
erasure occurs,.

If the police obtain possession of the USB stick, they can use
tools to search the "spare sectors". These are not accessible
from user-space all that easily, so you have to be content with
erasing the visible material. The spares could contain something
incriminating, that's if spares are even present. There are
manufacturer utilities that give more ready access to the
whole storage chip. Many of those utilities are not available
to the public. Only a few have "escaped" from factories.

On HDD (spinning rust), there is an Enhanced Secure Erase feature
supported in hardware, which wipes both user-sectors and "spares".
At least on some storage types, there are options for dealing
with the hidden spares problem. The USB stick is not particularly
feature rich, as hardware goes.

Paul

Paul wrote:

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1048576
count=12345

This utility wipes every sector, as long as the "offset" selected is
Partition0.

Are you claiming that the "of=blah" argument represents an offset?

"if" is for input file
"of" is for output file

Everything is a file :-)

Andy Burns wrote:
Paul wrote:

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1048576 count=12345

This utility wipes every sector, as long as the "offset" selected is
Partition0.

Are you claiming that the "of=blah" argument represents an offset?

"if" is for input file
"of" is for output file

Everything is a file :-)

Partition0 = start at Sector 0 where the MBR is located
(master boot record/partition table stored in 512 bytes)

Partition1 = start at beginning of first MSDOS partition (may not exist)
Partition2 = start at beginning of second MSDOS partition (may not exist)

If you just need to "purify" an individual partition and leave the
others alone, then \\?\Device\Harddisk0\Partition1 or
\\?\Device\Harddisk0\Partition2 might be your intended target.

The command also supports "seek" and "skip", as explained in the
manual page at http://www.chrysocome.net/dd . It's possible to
use "dd" like a surgical knife... if you're good at arithmetic to
work out offsets.

*******

Using HxD, you can also scroll around when finished, and have a look
at how complete the destruction is. A person doing this, normally
seeks confirmation of the success of what they've done. When you
start this program as Administrator, it can open storage devices
as a raw collection of sectors. And a quick scroll will verify the
job is done correctly.

https://mh-nexus.de/en/hxd/

Paul

On 05/06/2020 00.30, Mike Easter wrote:
Peter Jason wrote:
does DOS have a wipe app?

A useful utility disk to have around for DOS tools is the 'original'
make-up of Hiren's boot CD, now at 15.2.Â* It has several 'erasers' for
DOS, DiskWipe, HDD Eraser, & Shredder.

If you don't want the whole bootable CD/USB toolkit, you can dl
individual files linked from the site/page, including the erasers.

https://www.hiren.info/pages/bootcdÂ* All in One Bootable CD which has
all these utilities

Later Hiren's did a Win PE type disk.Â* https://www.hirensbootcd.org/
Hiren’s BootCD PE

Don't use a "secure eraser" that is designed for rotating rust media. On
flash thumbs, just overwrite once.


--
Cheers, Carlos.

On 05/06/2020 00.22, Jason wrote:
In article ,
lid says...

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.

A Quick format does nospam says, but a full format (takes a LONG time)
does overwrite the data. It won't pass an NSA test - the data might be
recoverable, but not with "ordinary" means.

No, it will not be recoverable, on flash thumb media, by any means. The
charge is either there or not.


--
Cheers, Carlos.

Paul wrote:
Peter Jason wrote:
Does formatting several times effectively wipe a small thunb drive?

http://www.chrysocome.net/downloads/dd-0.6beta3.zip

(Instructions)

http://www.chrysocome.net/dd

Administrator Command Prompt.

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1M count=12345

Paul, no offense but can you please stop advising very dangerous tools
like 'dd' in cases where they absolutely not needed?

Yes, in your - very long - story you *do* say to be careful, but
that's like saying be careful when advising someone to use a handgun to
hammer in a nail.

The OP (Peter Jason) is not even aware (no critcism intended) of
something as simple as unticking the 'Ouick-Format' option when doing a
'Format', so why advising something as complex and dangerous as 'dd'?

So *please* next time you advise 'dd' (et al), look at the need, the
context and most of all the (knowledge of the) person asking for help.
Thank you.

[...]

Carlos E.R. wrote:

The charge is either there or not.

Or for QLC drives, it may be 1/4, 1/2 or 3/4 there ...

Frank Slootweg wrote:
Paul wrote:
Peter Jason wrote:
Does formatting several times effectively wipe a small thunb drive?
http://www.chrysocome.net/downloads/dd-0.6beta3.zip

(Instructions)

http://www.chrysocome.net/dd

Administrator Command Prompt.

dd if=/dev/zero of=\\?\Device\Harddisk0\Partition0 bs=1M count=12345

Paul, no offense but can you please stop advising very dangerous tools
like 'dd' in cases where they absolutely not needed?

Yes, in your - very long - story you *do* say to be careful, but
that's like saying be careful when advising someone to use a handgun to
hammer in a nail.

The OP (Peter Jason) is not even aware (no critcism intended) of
something as simple as unticking the 'Ouick-Format' option when doing a
'Format', so why advising something as complex and dangerous as 'dd'?

So *please* next time you advise 'dd' (et al), look at the need, the
context and most of all the (knowledge of the) person asking for help.
Thank you.

[...]

Unticking Quick Format doesn't do a thing.

Untick Quick Format = clusters ignored entirely, $MFT or FAT written
Select Quick Format = clusters are *read* verified (no writes)

I'm providing security advice, where you've put something
on media you regret, and seek to remove it. That's what
"dd" is for.

I did *not* suggest this utility for a reason. I'm not
convinced it works properly. It takes a long time to
run, and while in theory it is supposed to clean between
the "teeth" of the $MFT, I'm not sure it is working as
it should.

https://docs.microsoft.com/en-us/sys...nloads/sdelete

On hard drives, the platform provides Enhanced Secure Erase.
As proposed and pushed through the ATA standard by the
guy at CMRR. Now, *that's* a proper solution. It even
makes a best effort to overwrite spares.

But USB sticks don't have that.

"dd" remains perfectly viable for the job, and other
than spares sectors being inaccessible from user-land,
does the job short of dropping the USB stick "in the chipper".
The manufacturer utility used to commission USB sticks,
would do a better job, but only a few of those are
in the hands of users (escaped from the factory).

*******

There are plenty of things you can regret doing on a computer.

Backups cover quite a few of them.

People don't ask these questions unless they have a reason.

Paul

On Fri, 05 Jun 2020 00:11:38 +0200, Sjouke Burry
wrote:

On 05.06.20 0:03, Peter Jason wrote:
On Thu, 04 Jun 2020 18:00:43 -0400, nospam
wrote:

In article , Peter Jason
wrote:

Does formatting several times effectively wipe a small thunb drive?

formatting, which only needs to be done once, just marks it as blank,
however, the data is still there and can potentially be scavenged.

if you want to wipe the data to prevent that, you will need to write
zeros to all blocks, usually called a secure erase and only one pass is
needed.
Thanks, does DOS have a wipe app?

You dont need a wipe app.
Just empty the stick.
then write some useless file(s) until the stick is full.

Thanks, this seems to work, and it's fast. All I have to do is to
copy movies across up to the USB limit.