Can A Mechanical Hard Drive Really Be 'Securely Wiped'?

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You clearly don't have the foggiest understanding of what an analogy is.

If I had said that reading past the end of tape marks on a tape was like scanning a hard drive, then it would have been an analogy and a very bad one at that. I made no such statement.

Also, you're the only one here claiming to be a professional in computer security. Whether or not you actually are is another question. I've met people who claimed to be security professionals who had zero knowledge of the subject. One in particular couldn't even plug a firewall in correctly.

You may consider completely destroying a hard drive for information security. But is it worth the time and effort?

If the drive contains extremely sensitive information, yes. Was it from a home computer? Just wipe it securely and reinstall an OS on it. Without the right equipment no one will be able to extract old information from it. You'll have to remove the platters, do some kind of magnetic analysis on it and retrieve the data. That's only worth time and effort if there is really interesting data on the drive.

There's also drive encryption which makes data retrieval even harder. I wouldn't be surprised if this was the case with computers used in organisations which handle sensitive data.

Analog circuit design to investigate the disk platter directly may be a lost art, but I think there are still a few people with that sort of knowledge. There may even be a few who also know the latest in digital signal processing techniques to look for the ones and zeros without having to consult anyone else.

Regardless of whether or not a 'hard-drive' can be "securely wiped", I had once found myself dismantling a hard-drive, and breaking apart the hard-drive's disk (the old school approach is truly secure).

The old desktop system was brought to an Ewaste recycling facility - with no further concerns for hard-drive security.

The physical destruction route is obviously likely to be very effective if carried out competently, but my original post was focussed on software-orientated solutions.

One interesting avenue of approach that I've seen recently involves encryption. Overwrite a disk with random ones and zeros, encrypt it, format it, then overwrite again. Foolproof?

If you want to erase the contents of a hard drive, the best way to do it is using HDParm to initiate an ATA Secure Erase. It works at a lower level than using DD.

I read no mention of that useful tool, Universal Boot Disk. It's more than a decade since I downloaded (it's free) my copy, and it may have changed, but it has a zeroing facility which works really well, and is actually one of the least clunky tools available. Security services usually specify zeroing 9 times to be sure of total wipe.

My go to for erasing is DBAN. My needs are normal, commercial so the default option is fine for me but it does offer more secure erase options that take longer.

I see disk wipe security discussions like bank safe discussions. Perfection may be possible but is usually not worth the cost.

I try for a wipe level where the cost/time to retrieve is many times the value of what was there. I assume that people with the knowledge or money to the recovery will go after better stuff.

https://www.lifewire.com/how-to-erase-a ... an-2619148