248
votes
Why didn't OSes securely delete files right from the beginning? And why do they still not do this?
Because of the following reasons:
Performance - it takes up resources destroying files. Imagine an application that uses hundreds or thousands of files. It would be a huge operation to securely ...
- 34k
166
votes
Accepted
Wiping an SSD with Parted Magic seemed too quick
Modern SSDs use a technology called SED which allows instant erasure. It works by transparently encrypting the entire drive and keeping the key on the drive. ATA Secure Erase is then implemented by ...
- 66.5k
108
votes
Accepted
Why didn't OSes securely delete files right from the beginning? And why do they still not do this?
Instead of another "You are wrong because" answer I'd like to take a slightly different approach:
Early computer OS's were written by programmers for programmers. Any one who programs and knows what ...
- 1,988
96
votes
Why didn't OSes securely delete files right from the beginning? And why do they still not do this?
It doesn't have to be corrected because it's not a fault.
The pointers to the file are deleted, and the area the file occupied is marked as free space. The drive then overwrites this area in its own ...
- 1,071
75
votes
Why didn't OSes securely delete files right from the beginning? And why do they still not do this?
You seems to have a wording problem with the delete term and a wrong expectation about what the functionality should do.
You can check the simple definition on the Merriam-Webster website:
delete: ...
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51
votes
Accepted
Does the destruction of sensitive information limit the choice of hard drives to non-flash based devices?
Data destruction is a technique of last resort. If you are planning to use a new storage device, you should use full disk encryption. This allows you to either destroy the encrypted master key or ...
- 66.5k
51
votes
Accepted
How can data from VirtualBox leak to the host and how to avoid it?
You are doing it the wrong way around: you have an untrusted host system running a hypervisor and you are trying to run a trusted environment inside this untrusted host. But, the untrusted host system ...
- 198k
48
votes
Accepted
To what extent does formatting a disk (securely) remove its data?
Quick-formatting a hard disk simply erases the filesystem's structures and tables and writes new ones in place, giving the illusion of a brand new disk. Old data is simply overwritten as and when ...
- 135k
46
votes
Accepted
Erased encrypted HDD, then secure erased 10% of it before selling it - is it safe?
Has the data been securely erased beyond any doubt? No. Does it matter in practice? Probably not, at least for any sensible domestic/company threat model.
For the purposes of this answer I will ...
- 135k
44
votes
Permanently erasing a file
Yes, most likely. However there can always be edge cases:
SSDs are doing wear leveling etc., and will most probably not write your zeroes to the same cells your original data was written to. How the ...
- 1,111
43
votes
How to safely wipe a USB flash drive
To quote the ISM (Australia's military standards for cyber security).
Security Control: 0359; In flash memory media, a technique known as wear levelling ensures that writes are distributed evenly ...
- 1,359
40
votes
At what point is deleted data irrecoverable?
This depends a lot on what medium is used to store the data and what you consider "irrecoverable".
"Deleting" data mostly does not what most people think it does.
Simply put, after a standard ...
- 1,144
37
votes
Accepted
How completely wipe information of overwritten files and folder?
You have to stop thinking about this on the file level. For a storage device, all that matters is the sector. If one sector on a hard drive* is overwritten, the data in it is gone for good. There is ...
- 66.5k
30
votes
Accepted
Is a file shredder/secure erase necessary when you have full disk encryption turned on?
I would still recommend using secure delete in your scenario. Should your machine be compromised when you are logged in (malware etc), full disk encryption will not protect you from a undelete ...
- 1,224
29
votes
How can data from VirtualBox leak to the host and how to avoid it?
The data didn't "leak" onto the host. The data always was on the host to begin with. The files inside the guest are stored in the virtual hard drive file, and the virtual hard drive file is ...
- 391
24
votes
Accepted
I forgot to shred a file before deleting it (on Windows). How do I shred that part of file system now where the file was located?
First of all (just to be on the safe side) verify the file isn't in the Recycle Bin. If it is, choose Restore and of course shred the recovered file (or maybe you can shred it while inside the Recycle ...
- 22.8k
24
votes
Accepted
How to safely wipe a USB flash drive
Next time you're about to put sensitive data on a flash drive, consider encrypting it first! Strongly encrypted data is useless without the key, and if you securely erase the drive first, all that ...
- 10.2k
23
votes
Will completely wiping your hard drive remove all malware?
How deep down the rabbit hole do you want to go?
For OS level malware: Sure, wiping the hard drive is fine. To be extra sure, overwrite the entire hard drive with 0s manually using a secure erase ...
- 7,006
23
votes
Signal — Can message previews of the messages you send be disabled in the chats’ list of your addressee?
Signal's feature is aimed at restricting unintentional disclosure. The client itself is open source, so no one can stop me from creating a client that doesn't honor the time restrictions or similar.
...
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17
votes
Accepted
Privacy data concern: Facebook account appearing with a search for phone number, despite it never being added - what should I do?
There isn't much you can do about it besides deleting your Facebook profile (different from deactivating it - though I'm sure in both cases nothing is really deleted).
As for how Facebook got your ...
- 12.8k
17
votes
How to safely wipe a USB flash drive
A quick check at amazon.com shows 64GB USB drives in non-designer cases go for about $20. Less if you buy in bulk.
Since you want "quick and efficient" lets factor in the time needed to overwrite the ...
- 179
17
votes
Permanently erasing a file
So the question is: If you overwrite a file's data with, let's say, just using WriteFile Win API to overwrite all data with zeros, will that become unrecoverable?
Don't use the WIN API WriteFile to ...
- 5,001
13
votes
Does the destruction of sensitive information limit the choice of hard drives to non-flash based devices?
Tl;dr: Because you can never trust all storage drives to securely wipe themselves, you must plan as if none of your drives can be securely wiped.
Placing a dependency on the type of media is not the ...
- 34.1k
13
votes
Permanently erasing a file
One way to dispose of a file in a 100% reliable manner is to keep it on a separate HDD partition you can purge, or, better yet, on a separate medium you can afford to destroy.
If that's not practical,...
- 10.2k
12
votes
Accepted
Should a secure ATA erase be performed on a non-SSD drive?
Given that the device is not a solid state drive, should a secure ATA erase still be performed?
If you want to erase the data, you can use ATA Secure Erase. It is not meant only for solid state ...
- 66.5k
11
votes
Why didn't OSes securely delete files right from the beginning? And why do they still not do this?
For performance reasons. Deleting the file from the index, and declaring that the zone where the file was is now free and can be re-used is far more efficient that erasing all data over that zone.
- 14.7k
11
votes
Permanently erasing a file
Effectively, yes, overwriting the blocks used by a file will make it unrecoverable.
This can be done using sdelete on Windows, or shred on Linux.
- 72.7k
11
votes
At what point is deleted data irrecoverable?
While the current leading answer dives into the technical details of data recovery, I will (try to) take the broader approach.
How do we define "irrecoverable"?
Depending on the circle you may ...
- 3,032
10
votes
How to erase as much as possible an SSD without ATA Secure Erase?
I don't know why you say that SSDs implement ATA Security Erase improperly. Modern ones implement it using SED (which uses an encryption key known to the drive and stored in non-volatile memory for ...
- 246
9
votes
Accepted
How secure is the windows Cipher command?
Securely deleting data, otherwise known as “wiping” can be surprisingly difficult.
Overwriting data even once with “cipher.exe”, or any other tool, makes the data effectively gone. The old bugaboos ...
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