Disposing of deleted data.

On 3/28/2019 10:02 AM, nospam wrote:
neat, and works every day, instantly. Someone steals the machine, the
While the accepted permanent solution for a disk is to destroy the hard
drive, with today's technology, I wonder that is the case any longer.

Given the time, money and desire to access the data, it seems like the
electro-magnetic properties of the surfaces of the pieces of the platter
could be scanned. The scans could be mapped on to another disk to
recreate the damage disk. With the disk recreated on another computer
the contents could be read.

If it is not technically possible it will give the paranoids something
to worry about.

--
2018: The year we learn to play the great game of Euchre

On 28/03/2019 19.02, Keith Nuttle wrote:
On 3/28/2019 10:02 AM, nospam wrote:
neat, and works every day, instantly. Someone steals the machine, the
While the accepted permanent solution for a disk is to destroy the hard
drive, with today's technology, I wonder that is the case any longer.

Given the time, money and desire to access the data, it seems like the
electro-magnetic properties of the surfaces of the pieces of the platter
could be scanned.Â* The scans could be mapped on to another disk to
recreate the damage disk.Â* With the disk recreated on another computer
the contents could be read.

If it is not technically possible it will give the paranoids something
to worry about.

:-D

If I were to destroy a drive, I would simply open it up and rub the
plate with a strong magnet :-p

--
Cheers, Carlos.

In article , Keith Nuttle
wrote:

On 3/28/2019 10:02 AM, nospam wrote:
neat, and works every day, instantly. Someone steals the machine, the

i didn't write what you quoted.

While the accepted permanent solution for a disk is to destroy the hard
drive, with today's technology, I wonder that is the case any longer.

destroying the disk guarantees that it's not recoverable.

Given the time, money and desire to access the data, it seems like the
electro-magnetic properties of the surfaces of the pieces of the platter
could be scanned. The scans could be mapped on to another disk to
recreate the damage disk. With the disk recreated on another computer
the contents could be read.

they'd need to piece together all of the pieces and in the proper
arrangement with little to no missing pieces, and even then, good luck.

it might be theoretically possible to get *some* data if there are a
few large pieces (and not without a ****load of effort and expense),
but if it's in a zillion tiny pieces, forget it.

If it is not technically possible it will give the paranoids something
to worry about.

paranoids worry about all sorts of ****, much of which is not
technically feasible.

In article , Carlos E.R.
wrote:


What apparently the OP wants is to delete permanently whatever he
deletes, and for this he is prepared to copy everything to another disk,
format fully, and restore the data. This process takes many hours. And
would have to be repeated often, as soon as he does some work with that
sensitive material.

it only needs to be done once.

Every time he works on the machine with sensitive material.

nope. only when erasing the drive. it also doesn't take that long
unless it's a very high capacity drive, such as 10tb.

He needs to erase the drive everytime he works on that sensitive
material.

no he doesn't.

He dis not say anything about giving the drive, he is keeping
it. So everytime he works on the data, he needs to erase it.

if he's keeping the drive, then there's no need to erase it each time.
there is absolutely no benefit in that.

Or, encrypt it instead. Just once.

or that.

On 03/28/2019 2:04 PM, nospam wrote:
In article , Keith Nuttle
wrote:

On 3/28/2019 10:02 AM, nospam wrote:
neat, and works every day, instantly. Someone steals the machine, the

i didn't write what you quoted.

While the accepted permanent solution for a disk is to destroy the hard
drive, with today's technology, I wonder that is the case any longer.

destroying the disk guarantees that it's not recoverable.

Given the time, money and desire to access the data, it seems like the
electro-magnetic properties of the surfaces of the pieces of the platter
could be scanned. The scans could be mapped on to another disk to
recreate the damage disk. With the disk recreated on another computer
the contents could be read.

they'd need to piece together all of the pieces and in the proper
arrangement with little to no missing pieces, and even then, good luck.

it might be theoretically possible to get *some* data if there are a
few large pieces (and not without a ****load of effort and expense),
but if it's in a zillion tiny pieces, forget it.

If it is not technically possible it will give the paranoids something
to worry about.

paranoids worry about all sorts of ****, much of which is not
technically feasible.


Come on guys, if you are truly paranoid use the right tools for the job.

Fer-instance

https://www.blue-pencil.ca/hard-driv...-why-it-works/

Enjoy, Rene

On 3/28/2019 3:04 PM, nospam wrote:
In article , Keith Nuttle
wrote:

On 3/28/2019 10:02 AM, nospam wrote:
neat, and works every day, instantly. Someone steals the machine, the

i didn't write what you quoted.

While the accepted permanent solution for a disk is to destroy the hard
drive, with today's technology, I wonder that is the case any longer.

destroying the disk guarantees that it's not recoverable.

Given the time, money and desire to access the data, it seems like the
electro-magnetic properties of the surfaces of the pieces of the platter
could be scanned. The scans could be mapped on to another disk to
recreate the damage disk. With the disk recreated on another computer
the contents could be read.

they'd need to piece together all of the pieces and in the proper
arrangement with little to no missing pieces, and even then, good luck.

it might be theoretically possible to get *some* data if there are a
few large pieces (and not without a ****load of effort and expense),
but if it's in a zillion tiny pieces, forget it.

If it is not technically possible it will give the paranoids something
to worry about.

paranoids worry about all sorts of ****, much of which is not
technically feasible.

I also suspect that if you would acid treat the platter and disolve the
iron oxide coat that would distroy the data.

--
2018: The year we learn to play the great game of Euchre

In article , Keith Nuttle
wrote:


I also suspect that if you would acid treat the platter and disolve the
iron oxide coat that would distroy the data.

that would work.

pulverizing it into powder would also work.

another way is bake it in an oven above it's curie temp.

however, for most people, drilling a hole through the platters will
suffice.

Carlos E.R. wrote:
On 28/03/2019 15.42, nospam wrote:
In article , Carlos E.R.
wrote:

But if you really want to prevent access, destroy the platters. Which
will destroy the HDD.
not needed except for the truly paranoid.
On the contrary, it makes things simpler.
destroying a disk is anything but simple, and not as easy as you might
think.
Me never said anything about destroying the disk. That was somebody else.
yep, and that's what i was replying to.

What apparently the OP wants is to delete permanently whatever he
deletes, and for this he is prepared to copy everything to another disk,
format fully, and restore the data. This process takes many hours. And
would have to be repeated often, as soon as he does some work with that
sensitive material.
it only needs to be done once.
Every time he works on the machine with sensitive material.
nope. only when erasing the drive. it also doesn't take that long
unless it's a very high capacity drive, such as 10tb.


He needs to erase the drive everytime he works on that sensitive
material. He dis not say anything about giving the drive, he is keeping
it. So everytime he works on the data, he needs to erase it.

Or, encrypt it instead. Just once.

If you're a paranoid:

1) Think about methods of computer operation that *cannot* leak.
Then notice how impractical they are. Linux LiveDVD for the win.
Read-only OS. Home is on a RAMDisk. Still potential for splatter
onto a data drive, if you're not careful.

2) Hone your "leakage detection test plan".

If you're not using this, what the hell are you doing ?
(You can scan every sector of a disk with this. Use
Run As Administrator to enable that mode. Use fixed data
patterns that will be easy to detect.)

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

3) Once you have a plan, and tools, now, do some testing.
Since everything leaks like a sieve, be prepared for
*lots* of surprises. Even with encryption, the method
may temporarily store something in %temp%, leaving "footprints".

4) If you start with quality materials, your test plan
will be a bit shorter. This article is disingenuous, with
its references to Guttmann 35-pass. 35-pass is not the problem.
Knowing *where* to look for leaked data, is the benefit of
program designs like this. If an erasure program writes zeros
over a leak, even one pass, that's a big win compared to...
doing nothing, which is what other programs might be doing for you.

https://en.wikipedia.org/wiki/Eraser_%28software%29

The problem is, people who spend all day looking at Fluffy
Cat Photos, expect others to dream up "bulletproof" solutions.
As if we give a damn! If you have something to hide, do
your own homework! Make a plan FFS! It's not that hard.

Giving you a hex editor, is your bread crumb.

I did my own test of SDelete a few days ago... and it
leaked like a sieve. But, I wasn't surprised. Test only
purpose-built software, written by paranoids, if you
expect results. The staff at Sysinternals cannot be
expected to be "paranoid enough" for this task. I did the
test, out of boredom, not because I particularly expected
a good result. sdelete64.exe -z C:

Paul

On 28/03/2019 00.57, Paul wrote:


You can also use a utility that does Secure Erase or
Enhanced Secure Erase, which are features of the
ATA command set (good for IDE or SATA drives, but not SCSI).
In those cases, the drive erases itself, and that takes hours
too.

And does not waste CPU. You can use the computer for other things.

--
Cheers,
Carlos E.R.

Keith Nuttle wrote:


I also suspect that if you would acid treat the platter and disolve the
iron oxide coat that would distroy the data.

Do you really think they use those materials any more ?

Recording mode has gone from longitudinal recording to
perpendicular recording (PMR), and so the stackup had
to change for that to work well. The 1's and 0's
stack vertically into the platter surface. The back
of the magnetic circuit, is a keeper layer, underneath the
other layers of the plate-up stack. The keeper layer, down
below the surface, is the one I would count on for an acid
attack.

The outside of the platter has a polymer lubricant.
The first layer is "bonded" to the platter, with
a liquid layer above that. It's similar to that "miracle
car wax" liquid, that polymerizes after you apply it,
and you buff off the excess that didn't polymerize.
So the first problem, is the acid "wetting" the surface.

If any precious metals are used in the stack,
they might be a barrier to your acid attack.
There could be platinum or ruthenium in the stackup.
Platinum can be attacked with Kings Reagent, boil in
a fume hood for two hours... I learned about this
in high school Chem.

https://en.wikipedia.org/wiki/Aqua_regia

There is also a nice chromic acid solution that the "dish washer"
person in the government lab I worked in, used to use. That
eats "dirt", common earth, and makes your porcelain vessels
sparkling white. I used to clean my own labware using that
stuff, and it's reusable so you don't pour it down the sink :-/
All my glassware was "Zestfully clean". The glassware
had to be clean of certain organics, to a ppb level.

Platter design is more dynamic than it used to be.
The chemistry in every generation of disk drives
can be different. For example, they're changing
from aluminum back to glass platters, so the stackup
will be slightly different, right next to the substrate.
The reason they're doing that, is the disk drive companies
only want to make "large" hard drives now, so six or
seven platters inside each drive is more the "norm".
This meant making the platters thinner, and eventually
aluminum is no longer strong and rigid enough. Glass
sucks as a material, but... nothing stops engineering.

If there is a "bad way to make cheap hard drives",
they'll find it :-/ You can count on it.

I really miss the hgst site since WDC bought them. It
was the only source of whizzy articles (written by former
IBM researchers) on hard drive tech. Now, we have... nothing.
I can no longer reliably provide links on modern stuff.
My only source is gone. Now, you'd have to bob through
patent filings. Which is fun... if you know the
right search term to kick off a search. The patent filings
are slightly more illuminating than the IBM articles, but
the IBM articles were "convenient serving portions" and
easier to digest.

Paul

On 28/03/2019 21.32, Paul wrote:
3) Once you have a plan, and tools, now, do some testing.
Â*Â* Since everything leaks like a sieve, be prepared for
Â*Â* *lots* of surprises. Even with encryption, the method
Â*Â* may temporarily store something in %temp%, leaving "footprints".

Which is why I said "full disk encryption" ;-)

--
Cheers, Carlos.