Episode #562

Beyond the Factory Reset: How to Truly Erase Your Data

Think a factory reset protects your old data? Herman and Corn reveal why your digital "ghosts" might still be lurking on your old devices.

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In the latest episode of My Weird Prompts, hosts and brothers Herman and Corn sit down in their Jerusalem living room to tackle a common but often misunderstood dilemma: how to properly dispose of old electronics without handing over a goldmine of personal data to strangers. The discussion was sparked by their housemate Daniel, who found himself staring at a box of decade-old laptops and phones, wondering if a simple factory reset would be enough to protect his legacy of photos and financial documents.

The Library Analogy: Why "Delete" Doesn't Mean "Gone"

Herman, the resident tech expert with a self-professed surplus of encrypted hard drives, begins by debunking the "physical document" myth of digital data. Most users assume that deleting a file is like throwing a paper in the trash, but Herman argues that digital data is far more "ghost-like."

To explain this, he uses the "Library Analogy." Imagine a massive library with millions of books. When you delete a file on a traditional Hard Disk Drive (HDD), you aren't burning the book; you are simply ripping the index card out of the card catalog. The book—the data—remains on the shelf. The operating system simply marks that space as "available." Until a new "book" is written directly over that spot, the original data remains perfectly readable to anyone with basic recovery software.

This led to the "mythos" of data destruction in the 1990s, such as the Gutmann method, which suggested overwriting a drive 35 times to remove magnetic traces. While Herman notes this was likely overkill even then, it highlights how difficult it used to be to ensure data was truly gone from mechanical, spinning platters.

The Rise of Flash Storage and the Cryptographic Erase

The conversation then shifts to modern hardware. Most devices today—smartphones, tablets, and newer laptops—use Solid State Drives (SSDs) or flash memory. Herman explains that the rules for these devices are fundamentally different thanks to default encryption.

On a modern iPhone or Android device, data is scrambled into "gibberish" the moment it is written. The "key" to translate that gibberish is stored in a dedicated, highly secure hardware component like Apple’s Secure Enclave. When a user performs a factory reset on these devices, the phone doesn't spend hours overwriting every byte of data. Instead, it performs a "cryptographic erase." It destroys the encryption key.

Herman likens this to a safe built into a mountain. If you melt the only key in a furnace, the safe’s contents are effectively lost forever, even if the safe itself remains. For modern mobile users, this makes the factory reset an incredibly powerful and secure tool.

The Windows and Mac Divide

However, the brothers warn that laptops are a bit more complicated. While modern Macs with T2 or M-series chips function much like iPhones, Windows machines can be a "wild west" of security settings. Herman points out that many older Windows 10 or 11 laptops—especially those running "Home" editions—may not have BitLocker encryption turned on by default.

If a user resets a non-encrypted Windows laptop using the standard settings, their "plain text" files might still be sitting on the drive. For these users, Herman recommends selecting the "Fully clean the drive" option during the Windows reset process. While it takes significantly longer, it ensures the drive is overwritten with zeroes, making recovery much more difficult for the average buyer.

The Danger of Old Habits: SSDs vs. DBAN

One of the most critical warnings Herman issues involves the use of legacy wiping tools on modern hardware. Many tech-savvy users still rely on tools like DBAN (Darik’s Boot and Nuke), which were designed to hammer mechanical drives with random data.

Herman explains that using these on an SSD is not only inefficient but potentially ineffective due to "wear leveling." To extend the life of a flash chip, the drive’s internal controller constantly moves data around to ensure no single cell wears out too quickly. This means a software tool might think it has overwritten the entire drive, while the controller has actually hidden original data in "over-provisioned" blocks that the software can't see.

For SSDs, Herman’s advice is clear: use the manufacturer’s own utility (such as those from Samsung or Western Digital) to trigger a "Secure Erase" or "Sanitize" command. This tells the controller to flush the cells at a hardware level using a specific voltage spike, ensuring total data clearance.

The Final Resort: Physical Destruction

The episode concludes with a look at "dead" tech. If a laptop won't turn on, you can't run a secure erase, but that doesn't mean the data is dead. The storage chips are likely still functional and could be harvested.

For devices that are truly junk and destined for the recycling bin, Herman advocates for the "gold standard" of home security: physical destruction. For old HDDs, this means using a power drill to put several holes through the internal platters. For SSDs, it requires a bit more precision; one must locate the individual memory chips on the circuit board and ensure they are physically cracked or crushed.

Ultimately, Herman and Corn’s discussion serves as a reminder that identity theft is a "game of pieces." A single discarded drive might contain a forgotten tax return, a browser cache of passwords, or a scan of an ID. By understanding the difference between the "index card" and the "book," and by leveraging modern encryption tools like FileVault and BitLocker today, users can ensure that when they finally retire their tech, their private lives stay private.

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Episode #562: Beyond the Factory Reset: How to Truly Erase Your Data

Corn
Hey everyone, welcome back to My Weird Prompts. I am Corn, and I am sitting here in our living room in Jerusalem with my brother, the man who probably has more encrypted hard drives than he has socks.
Herman
Herman Poppleberry at your service, Corn. And you are not wrong. I actually did a count last week and the drives are winning by a margin of about three to one.
Corn
That is slightly concerning, Herman, but it makes you the perfect person to talk about what we are diving into today. Our housemate Daniel was actually going through a box of his old gear this morning, and it sparked a really interesting question. He was looking at this stack of old laptops and phones from, oh, probably ten or fifteen years ago, and he was wondering what the real risk is if he just hands them off to a recycling center or sells them for parts.
Herman
It is a classic dilemma. Daniel was asking me if a factory reset is actually enough to keep his old photos and bank statements from falling into the wrong hands. And the answer, as with most things in the world of data security, is that it depends entirely on what kind of hardware you are talking about. It is one of those things where the common wisdom has changed so much in the last decade that if you are following advice from two thousand ten, you are probably doing it wrong.
Corn
That is what I want to dig into. Because I think most people have this mental model of data being like a physical document. You know, you throw it in the trash, and it is gone. Or maybe you shred it, and then it is really gone. But digital data is a bit more ghost-like, right? It leaves these echoes.
Herman
That is a great way to put it. The library analogy is the one I always go back to. Imagine a massive library with millions of books. When you delete a file on an old school hard disk drive, you are not actually burning the book. You are just going to the card catalog and ripping out the index card. The book is still sitting on the shelf. The librarian just does not know where it is anymore, so the next time a new book comes in, they might just shove it right on top of the old one.
Corn
Right, so until that space is overwritten by something else, that original data is just sitting there, waiting for someone with the right tools to come along and read it.
Herman
Exactly. And back in the day, with those mechanical drives that had spinning magnetic platters, you could actually use specialized software to look for those magnetic traces. There was this famous researcher named Peter Gutmann who wrote a paper back in nineteen ninety-six about how you supposedly needed to overwrite a drive thirty-five times to truly erase the data because of how the magnetic heads worked.
Corn
Thirty-five times? That sounds like it would take a week.
Herman
It took forever. And the funny thing is, even back then, it was probably overkill. But it created this mythos around data destruction. People thought if they did not do a seven-pass or a thirty-five-pass wipe, the government could still read their old emails. But the world has moved on. We are not really using those spinning platters as much for our personal devices anymore. Almost everything Daniel was looking at in his box—his old phones, his newer laptops—they all use flash memory, or Solid State Drives. And that changes the game completely.
Corn
So, let us talk about that. If I have a phone from five years ago and I hit factory reset, what is actually happening under the hood? Is that index card just being ripped out, or is something more substantial going on?
Herman
This is where it gets really interesting, and honestly, a bit more reassuring. On a modern smartphone, whether it is an iPhone or an Android device, the data is encrypted by default. This is something called file based encryption or full disk encryption. When you set up the phone, it generates a unique encryption key that is stored in a special, secure part of the hardware called the Secure Enclave on Apple devices or the Trusted Execution Environment on Android.
Corn
Okay, so every bit of data on there is scrambled into gibberish unless that key is present.
Herman
Precisely. So when you perform a factory reset on a modern phone, the device does not actually go through and overwrite every single zero and one on the storage chip. That would take a long time and put a lot of wear and tear on the flash memory. Instead, it does something called a cryptographic erase. It simply destroys the encryption key.
Corn
Oh, I see. So the scrambled data is still technically there on the chip, but without that key, it is mathematically impossible to turn it back into anything useful?
Herman
Exactly. It is like having a safe that is built into a mountain, and the only way to open it is with a specific key. If you melt the key in a furnace, it does not matter if the safe is still there. No one is getting in. For most people, and for Daniel's old phones, a factory reset is actually incredibly secure because of this. Once that key is gone, the data is essentially noise.
Corn
That is a relief for the phone side of things. But what about laptops? I know a lot of people who still have old Windows laptops or Macbooks from the mid-twenty-teens. Are they using the same kind of encryption?
Herman
Not always by default, and that is the catch. On a Mac, Apple has been pretty good about this. If you have a Mac with a T-two security chip or one of the newer Apple Silicon chips like the M-one through M-four, they handle encryption much like an iPhone does. When you go into the system settings and choose Erase All Content and Settings, it is doing that same cryptographic erase. It is fast, and it is very secure.
Corn
But what if I have an older PC? Say, a Windows ten or Windows eleven laptop that I bought in twenty-sixteen or twenty-eighteen?
Herman
That is where you have to be more careful. If you did not manually turn on BitLocker, which is the Windows encryption tool, then your data is likely sitting there unencrypted. Even on Windows eleven, if you have a Home edition and the hardware didn't support automatic Device Encryption, your files are just plain text on that drive. If you just do a standard Windows reset, there is a chance that a lot of that data could be recovered using basic off the shelf software.
Corn
So if Daniel has one of those older Windows machines, he shouldn't just hit reset and put it on a resale site?
Herman
I would not recommend it. For those older drives, you want to use a tool that actually performs a full wipe. Windows has a built in option during the reset process where it asks if you want to just remove your files or fully clean the drive. You always want to choose fully clean the drive if you are giving it away. It takes longer—maybe an hour or two depending on the size—but it actually writes zeroes over the entire drive.
Corn
I remember Daniel mentioning a tool called Clonezilla, and there is another one called D-B-A-N, or Darik's Boot and Nuke. Are those still relevant, or are they relics of the spinning drive era?
Herman
D-B-A-N is a classic. It is great for those old mechanical hard drives. You boot from a U-S-B stick, and it just hammers the drive with random data. But here is a huge warning: do not use D-B-A-N on a Solid State Drive.
Corn
Why not? Is it because of the wear and tear you mentioned earlier?
Herman
That is part of it, but it is also because of how Solid State Drives manage data. They have this thing called wear leveling. Because each little cell in a flash chip can only be written to a certain number of times before it dies, the controller inside the drive constantly moves data around to make sure the cells wear out evenly.
Corn
So if I tell the software to write a zero to sector five hundred, the drive might actually write it to sector nine thousand to save the life of the chip?
Herman
Exactly. And it keeps a map of where everything is. This means that a software tool like D-B-A-N might think it has overwritten the whole drive, but the drive's controller could be hiding some old data in what it calls over-provisioned space or bad blocks that are no longer being used for active storage but still contain information.
Corn
That sounds like a bit of a nightmare for security. If the drive is lying to the operating system about where the data is, how can you ever be sure it is gone?
Herman
It is a challenge. That is why for Solid State Drives, you really want to use the manufacturer's own utility. Most companies like Samsung or Western Digital have their own software that can send a Secure Erase or a Sanitize command directly to the drive's controller. That command tells the controller to apply a higher voltage to all the cells at once, essentially flushing them out in one go. It is much more effective than trying to overwrite it from the outside.
Corn
This brings up an interesting point about the unintended consequences Daniel mentioned. We are talking about selling or recycling, but what about just throwing things away? You see people sometimes just tossing an old tower P-C into a dumpster. That seems like a goldmine for someone who knows what they are looking for.
Herman
Oh, it absolutely is. Identity theft is often a game of pieces. There was a famous case back in twenty-twenty where Morgan Stanley was fined sixty million dollars because they didn't properly decommission old servers, and some of those ended up being sold with customer data still on them. For an individual, maybe they do not get your whole life from one drive, but they get an old tax return, a few saved passwords from a browser you forgot to clear, and maybe some scans of your I-D. You put those together, and suddenly someone can open a credit card in your name.
Corn
I think people underestimate how much of their life is cached in places they do not look. It is not just the documents folder. It is the thumbnail cache, the temporary internet files, the hibernation files.
Herman
Exactly. Even if you deleted a photo, a tiny thumbnail of it might still exist in a system folder somewhere. This is why I always tell people: if you are not going to sell the device, if it is truly junk, do not just throw it away. Physical destruction is the only way to be one hundred percent sure if you are dealing with unencrypted drives.
Corn
When you say physical destruction, are we talking about the classic drill through the hard drive?
Herman
That is the gold standard for home users. If you have an old mechanical drive, taking a power drill and putting three or four holes through the platters makes it essentially impossible for anyone but a high level state laboratory to recover anything. For a Solid State Drive, you have to be a bit more thorough because the data is stored on these tiny little chips. You need to make sure you actually crack or crush the individual memory chips on the circuit board.
Corn
I can just imagine you in the backyard with a hammer and a pair of safety goggles, Herman.
Herman
Hey, it is therapeutic! But honestly, most people do not need to go that far. If you are a regular person with a laptop from the last five or six years, turning on encryption today is the best thing you can do for your future self. If you use FileVault on a Mac or BitLocker on Windows, then when the day comes to get rid of that computer, you can just wipe the key and sleep easy.
Corn
That is a great proactive tip. But what about the stuff that is already in the box? Daniel's old phones and laptops are already there. Let's say he finds an old laptop that does not even turn on anymore. He can't run a secure erase if the motherboard is dead. What then?
Herman
In that case, you have to go physical. You can't trust that the data is gone just because the screen won't light up. The storage chip itself is probably still perfectly fine. If you can't boot it up to wipe it, you should pull the drive out. Most old laptops make it pretty easy to remove the hard drive with just a screwdriver. Once it is out, you can either put it in a cheap external enclosure to wipe it on another computer, or you can go the drill route if the drive itself is dead.
Corn
It is funny how we have moved from this era where we were worried about magnetic traces and thirty-five passes to an era where it is all about encryption keys. It feels like the battleground has shifted from the physical medium to the mathematics.
Herman
It really has. And that brings us to an even deeper level of data permanence. We have been talking about the hardware we own, but Daniel also brought up an interesting point about where our data goes after we think we have deleted it from the cloud. That is a whole different ballgame.
Corn
Right, because you can't exactly go to a data center and drill a hole through a server that belongs to a giant tech company.
Herman
Exactly. When you delete a file from a cloud storage service, you are essentially just sending a request for them to delete it. You have to trust their internal processes. Most of them have very strict policies where they mark the data as deleted, and then it is eventually overwritten as part of their normal operations. But you don't have that same level of absolute certainty that you do with a device you are holding in your hand.
Corn
It makes me think about the secondary market for these devices. You see these stories about people buying used phones on auction sites and finding that they can recover the previous owner's entire life. Is that still happening as much now that encryption is standard?
Herman
It is happening less with phones, but it still happens a lot with things like smart home devices, or even some printers. People forget that their office printer might have a hard drive in it that stores a copy of every document that was ever scanned or printed.
Corn
Wait, really? A printer?
Herman
Oh, absolutely. High end office copiers and printers often have internal storage. There have been cases where companies sold off their old office equipment and accidentally gave away thousands of sensitive medical records or legal documents because no one thought to wipe the printer's hard drive.
Corn
That is a terrifying thought. It is like our digital footprint is being leaked by the most mundane objects in our lives.
Herman
It really is. And it is not just printers. Think about your car. If you sync your phone to a rental car or a car you are about to sell, it might be downloading your entire contact list and your recent call history into the car's infotainment system.
Corn
I have definitely seen that. You get into a rental car and you see the previous five people's phones listed in the Bluetooth menu.
Herman
And if you are not careful, the car might still have their home address saved in the navigation system. So the lesson there is, whenever you are parting with anything that has a chip in it—a car, a printer, a smart fridge, whatever—you need to look for that factory reset option.
Corn
This is making me want to go through every room in our house and just start wiping things. But let's bring it back to the practical for a second. If someone is listening to this and they have a weekend project to clear out their old tech, what is the step by step?
Herman
Okay, here is the Herman Poppleberry certified protocol for secure disposal. Step one: identify the storage. Is it a phone, a modern laptop, or an old desktop?
Corn
Step two: check for encryption.
Herman
Right. If it is a phone or a newer Mac, just use the built in erase function. It is fast and secure. If it is a Windows machine, check if BitLocker or Device Encryption is on. If it is, a standard reset with the data erasure option is probably fine. If it is not, you want to do the long version of the reset that overwrites the drive.
Corn
And step three: if it is an old mechanical drive?
Herman
If you want to be extra sure, use a tool like D-B-A-N if the computer still works. If it doesn't work, take the drive out and use a drill. It is the only way to be sure.
Corn
And step four: don't forget the weird stuff. The printers, the old gaming consoles, the G-P-S units.
Herman
Exactly. Check the settings menu for a factory reset. And for heaven's sake, if you are selling a camera, take the memory card out! People forget their S-D cards in their cameras all the time.
Corn
That is a big one. You sell the camera and give away your entire vacation history for free.
Herman
It happens more than you would think. And honestly, the risk isn't just that someone will find your embarrassing photos. It is the metadata. Every photo you take has the location, the time, and the camera serial number embedded in it. If someone gets a thousand of your photos, they can basically map out your entire routine.
Corn
This really goes back to what Daniel was saying about unintended consequences. We think we are just getting rid of a piece of plastic and glass, but we are actually handing over a map of our lives if we aren't careful.
Herman
It is a responsibility. We spend so much time thinking about how to secure our data while we are using it—passwords, two-factor authentication, firewalls—but we often forget about the end of the life cycle. Secure data destruction is just the final chapter of good digital hygiene.
Corn
You know, it is interesting to think about the why behind all of this. Why is it so hard to truly delete something? In a way, it is a testament to how good we have become at making storage reliable. We have built these systems to be so resilient against accidental loss that they have become resilient against intentional deletion, too.
Herman
That is a profound point. We spent decades trying to make sure that a stray magnetic field or a power flicker wouldn't erase our precious data. We built error correction, we built redundant sectors, we built wear leveling. We made data incredibly sticky. And now we are finding that the stickiness is a double edged sword.
Corn
It makes me wonder what the future holds. As we move toward more exotic forms of storage, like D-N-A storage or glass based storage that is designed to last for thousands of years, how are we going to delete that?
Herman
Oh, that is going to be a fascinating challenge. If you have data etched into a piece of quartz glass that is designed to survive a fire, you might literally need a sledgehammer to delete your files. We are moving away from the era of soft storage and back into an era of hard storage, where the physical medium is almost indestructible.
Corn
It is like we are moving back to stone tablets, just much, much smaller ones.
Herman
Exactly. And the privacy implications of that are huge. Imagine if your medical records are stored on something that lasts ten thousand years. Who is going to be reading that in the year twelve thousand twenty-six?
Corn
Hopefully, by then, they will have better things to do than look at my old cholesterol levels. But it really highlights the importance of encryption. If the medium is permanent, the only way to have privacy is to make the data unreadable without a key that is temporary.
Herman
That is the ultimate takeaway. Encryption is the only way to truly delete something in a world of permanent storage. If the key is gone, the time scale of the storage doesn't matter.
Corn
I think that is a really empowering way to look at it. Instead of being afraid of our old tech, we can just be smart about how we manage the keys.
Herman
Precisely. And speaking of being smart, I should probably mention that if anyone is getting value out of these deep dives, we would really appreciate it if you could leave us a review on your podcast app or on Spotify. It genuinely helps other curious people find the show.
Corn
Yeah, it really does make a difference. We love seeing the community grow around these weird prompts that Daniel sends us.
Herman
And if you want to get in touch or see our back catalog, you can always head over to myweirdprompts dot com. We have all five hundred and fifty-four episodes there, and there is a contact form if you have a topic you want us to tackle.
Corn
Five hundred and fifty-four. Man, we have talked about a lot of stuff, Herman.
Herman
And we are just getting started, Corn. There is always more to dig into.
Corn
Well, I think I am going to go help Daniel with that box of gear. I suspect there is an old laptop in there that might need a quality session with your power drill.
Herman
I will go get my goggles.
Corn
Thanks for listening to My Weird Prompts. We will be back soon with another deep dive into the strange and wonderful world of technology and beyond.
Herman
Stay curious, and stay secure.
Corn
See you next time.
Herman
Goodbye!

This episode was generated with AI assistance. Hosts Herman and Corn are AI personalities.

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