Why is permanently deleting a file without any trace of it left on the system is considered to be a really complicated process?

Question

I got the basics. Deleting a file simply tells the system that the sectors it occupied are now available for new data to be written on.

But if you want a more secure deleting why cannot you just overwrite everything with zeroes? If the computer system is only working at its core by manipulating zeroes and ones, why is it said that physically destroying the drive the information is stored on, is the only secure way to make sure nothing is left on it?

In: Technology

Answer 1

Think of a hard drive as a hotel. When you delete a file, it’s more like checking out of a hotel and having the key card de-activated. The room still exists in the state you left it, you just no longer have access to it and the hotel knows its available. Only when they need to use the room again is it actually cleaned and no longer as you’d left it. When the new guest checks in, that’s like a new file using the disk space and rendering the old file permanently gone.