SecureErase (Category 4 - DoE 3 - Pass Secure Erase) Macintosh HD - in Terminal app

Question

SteveHS Author

Level 1

8 points

SecureErase (Category 4 - DoE 3 - Pass Secure Erase) Macintosh HD - in Terminal app

iMac -2012 - MacOS Catalina

I want to secure-erase my entire HD, not just the free space. The end goal is to sell my computer

I entered all of the required information into terminal to activate a category 4 secure erase.

After hitting the enter key, a line appears stating: "Ownership of the affected disk is required."

My question: What ownership information is required to activate the category 4 secure erase process?

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Below is a copy of all of the information displayed in the active Terminal window:

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Last login: Wed Oct 19 22:47:31 on ttys000

[—————— @ ———— iMac ~ % diskutil secureErase 4/Volumes/Macintosh\ HD]

Usage: diskutil secureErase [freespace] level

MountPoint | DiskIdentifier | DeviceNode

"Securely" (BUT SEE "man diskutil" FOR MODERN LIMITATIONS) erases either a

whole disk or a volume's freespace. Level should be one of the following:

0 — Single-pass zeros.

1 — Single-pass random numbers.

2 — US DoD 7-pass secure erase.

3 — Gutmann algorithm 35-pass secure erase.

4 — US DoE 3-pass secure erase.

Ownership of the affected disk is required.

Note: Level 2, 3, or 4 secure erases can take an extremely long time.

—————— @ ———— iMac ~ % []

iMac

Posted on Oct 19, 2022 11:41 PM

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Answer 1

SteveHS Author

Level 1

8 points

Oct 23, 2022 4:27 PM in response to John Galt

FYI: When I entered this environment (Recovery Mode), I did not have the option to adjust the security level (akin to being grayed out). I had full control of my mouse, I simply could not adjust the slider control.

The more I progress, the more I seem to be encountering many 'blockades' not customarily seen or experienced by the average end-user or more experienced developers/programmers.

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Answer 2

John Galt

Level 10

155,090 points

Oct 23, 2022 5:36 PM in response to SteveHS

SteveHS wrote:

"...never use these options for an SSD as SSDs don't work the same way as hard drives".

In that case, I've come to a dead-end.

Wait a minute — are you saying the storage device you are attempting to "secure erase" is a SSD and not a hard disk???

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Answer 3

John Galt

Level 10

155,090 points

Oct 23, 2022 7:15 PM in response to HWTech

HWTech wrote:

Also, I'm a bit curious about why you did not have Filevault enabled on this system if data security is so important now when preparing the computer for sale?

This very good question was discussed / beaten to death a while ago: Secure Empty Trash missing on El Capitan - Apple Community.

People were shocked, amazed, distressed and dismayed that Apple so callously removed a feature that had always been little more than a placebo.

Data does not suddenly become sensitive the moment you decide to destroy it, it's sensitive from the moment it is created, before multiple redundant copies become created on local storage, and perhaps distributed to servers all over the world.

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Answer 4

SteveHS Author

Level 1

8 points

Oct 23, 2022 8:08 PM in response to HWTech

"HWTech: I'm a bit curious about why you did not have Filevault enabled on this system if data security is so important now when preparing the computer for sale."

That was a serious misstep on my part.

Fortunately, I managed to get through that ten-year stretch unscathed.

Regarding all of the information you provided - Thank you for your generosity and for sharing your wealth of knowledge.

I'm a big fan of learning by doing despite the outcome. This experience could not have happened without everyone's feedback/assistance.

At this point, I've got a few options that I can try and see where it leads me.

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Answer 5

SteveHS Author

Level 1

8 points

Oct 23, 2022 8:18 PM in response to HWTech

I downloaded the Magician For Mac software. It's a ZIP file.

However, once the ZIP file is unzipped, the executable file contained within is an .exe file, not a .dmg file.

Why a software company would compress an .exe file and label it as a Magician For Mac ZIP file is beyond my comprehension.

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Answer 6

SteveHS Author

Level 1

8 points

Oct 24, 2022 12:34 PM in response to BobHarris

Having provided all of the essential information about my system and situation, is it possible to reach a reasonable consensus regarding the best way to move forward.

Is simply re-installing MacOS Catalina (over-writing the current MacOS operating system) sufficient considering the fact this system is operating off of an SSD?

Additionally, will I have the option to select the operating system via an online connection or would it be easier to access MacOS Catalina from my USB device? Please note: I will require instructions on how to boot into a USB device assuming this is an easier, considerably less convoluted method.

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