I was able to recover hundreds of files and pictures by using a third party $80 dollar software (EaseUS) which also suggested and pointed how to unlock the drive encryption for better results. I did and I was amazed, and very upset about, that most my data was still there. So there IS NO REAL factory reset. Want to get rid of your data? Get a really heavy hammer and smash your Mac.
It is commonly known that when doing a reset (reformatting the disk) that what is erased are the 'markers' that identify the files which are stored on the disk. Yes, the actual data remains unless and until it has been overwritten by a new file. I am sure that the same is true with a PC. The ONLY way to guarantee that the date is made to be completely unrecoverable is to use a program that overwrites the unused space with new ones and zeros. Such apps have the option to overwrite one time or multiple times for further security. Doing so will take time, like overnight, so allow for that. A hammer is not needed.
It is commonly known that when doing a reset (reformatting the disk) that what is erased are the 'markers' that identify the files which are stored on the disk. Yes, the actual data remains unless and until it has been overwritten by a new file. I am sure that the same is true with a PC. The ONLY way to guarantee that the date is made to be completely unrecoverable is to use a program that overwrites the unused space with new ones and zeros. Such apps have the option to overwrite one time or multiple times for further security. Doing so will take time, like overnight, so allow for that. A hammer is not needed.
I can't answer any arbitrary scenarios. All I can do is recommend the official procedure: What to do before you sell, give away, trade in, or recycle your Mac - Apple Support
When you do that, the hard drive will still have all of your encrypted data on it. But the data is encrypted, and at a very low-level. To anyone looking at the drive, at any level of detail, they will see only random data if they don't have the password.
If you wanted to, you could still write random data, or all zeros, 1's, whatever, over the entire disk. But you would have to start with the official procedure. Then write your data. Then repeat the official procedure. But that really isn't going to increase your security any way. Encrypted data without a password is the same as random data.
Apple did remove the option to write zeros, 1s, whatever to the drive, but that was only for social media and marketing concerns in our post-truth world. The process still works. You can still do it. But because of the way SSDs work internally, there would still be small bits of data that would not be overwritten. It is extremely unlikely for anyone to ever extract anything from those dark, low-level recesses of data. But that extremely low risk is enough to drive a good amount of social media click-throughs. So Apple got rid of it. And then later, Apple took the extra step to make sure that all data is encrypted before being written no matter what. When running a company at Apple's scale, it is a non-trivial task to manage internet lies.
Thank you Rosanara.
That has been my experience with PCs, and as the DoD recommends, overwrite bit by bit 7 times over, to guarantee the old data is no longer available, and that can take forever on these new huge drives.
But thank you for clarifying, we are still using the same technology for writing data, both on silicon chips and mechanical drives.
Bearded_Yoda wrote:
we are still using the same technology for writing data, both on silicon chips and mechanical drives.
No, we are not. All Apple Silicon computers are always encrypted. An encrypted file is the same as, or better than, overwriting it 7 times. But with an encrypted drive, the password is the key, literally. If you know the password, you can access the data. Someone who does not know the password cannot access the data.
If you haven't turned on FileVault, then the system automatically saves the password. That may be how you accessed the data. Turning on FileVault is now instant, since the drive is already encrypted. All it does is erase that saved password.
You are right again.
I did have to unlock the encryption with my Apple password so the third party undelete software could look at all the data.
The writing process may be similar as any drive, but Apple is a step ahead with the encryption.
So I give my Mac to a new owner who uses their Apple password and activate the machine on their account. Is then their data start overwriting my deleted data? What then if they decide to restore their delete data? They use the same software I used, enter their Apple password in unlock the encryption, and what do they see? Only their data? Or theirs and mine?
I could actually make that experience myself and see, as I can use a different Apple account as a new owner, then go through the process.
Erase All Contents and Settings DOES NOT wipe your data from the drive on Mac M1.
