If you delete the contents of a text file is it 100% protection?

Question

Information Security

Hey!
If, for example, you want to safely delete a file, then it can still be restored through special. Software, that is, this is not 100% protection, but if you delete the contents of a text file and save it, is this 200% protection against data recovery?
For example, extensions txt, doc, rtf, etc. , OS Windows (ntfs) and how will it be on Linux (ext4)?
It is also interesting about a similar method for images, open in the editor and cut out the picture.
Of course, provided that there is no software that can save the first option.
Thanks, it's just interesting.

Answer 1

In general, when you save your file, the program will create a new file with the changes made, and give the area occupied by the old file into free circulation. So the data will remain on the disk until the OS writes something there.

Answer 2

Now, if you fill the memory with dd from /dev/zero - then 300% protection :)

Answer 3

If you delete the contents of a text file, this is 100% protection

No.
This is "hell-knows-how much"% protection. Maybe the file will be written to the same area. Maybe to another. If, for example, this is an lvm volume distributed over several physical volumes - maybe even on another physical disk :)
Unambiguous, simple and affordable protection against recovery - write 100% harmless files. For example Linux distribution in ISO. You can do this several times. (deleting and writing again, and taking files of different lengths)

Answer 4

If once the file was saved, but then cleared, then the first version can be pulled out with special programs from the hard drive.