RE: What happens to information?
August 28, 2015 at 11:47 am
(This post was last modified: August 28, 2015 at 11:52 am by Tiberius.)
(August 28, 2015 at 4:44 am)excitedpenguin Wrote: I was asumming it worked when I said it was the best one. I don't know squat about this, though, nor do I pretend to. Not sure you got that.
This was a different kind of question overall but no one seemed to pick up on it so I'll just let it go. Maybe I didn't phrase it right. I'm sorry about that. Good to learn a few things about deleting software though.
So what kind of apps do that? Is CCleaner overwriting zeroes, or what? Does anyone know?
I believe CCleaner has an option to do a single pass overwrite. I'm not sure whether they zero the data or write random bits, or even all ones. In an ideal world, any three of those methods would be enough to wipe the data, however writing zeroes or ones is realistically better than random bits, because random number generators are not perfect and could potentially leave patterns in the data.
(August 28, 2015 at 5:09 am)Napoléon Wrote:(August 28, 2015 at 1:04 am)Tiberius Wrote: They sent the hard drive to three top data recovery companies and asked whether they could recover the data. All three refused to even take a look, because they knew it would be impossible: http://www.hostjury.com/blog/view/195/th...unaccepted
You sure it wasn't just because the prize is a paltry 40 bucks?
The prize for people applying was $40. They contacted three top data recovery companies and asked whether they would be able to do it; I don't believe a prize was mentioned to them, and the correspondence quoted on that site ended with the saleperson offering a quote. The fact that all three companies rejected the job demonstrates that the likelihood of data recovery in this instance is close to impossible, if not entirely impossible.
(August 28, 2015 at 11:18 am)Tartarus Sauce Wrote: I'm a tech nub so excuse me for my ignorance, but what's the difference between a pass overwrite and a normal overwrite (the typical "data delete" where the markers are switched to empty instead of occupied)?
There's no difference at all. The language is just very abstract to allow people to talk about storage without having to actually talk about what happens on the disk. On regular HDDs (not solid state), the data is stored in magnetized regions on the disk. The regions have a polarity which is either N/S (North then South) or S/N (South then North). One of these is considered a "1", the other a "0". Nothing gets overwritten or "switched to empty", but rather the polarities of the regions get changed. If you wanted the "zero" the disk, you would just set all the regions to the same polarity (e.g. N/S).
Now there is a difference between a multi-pass overwrite and a single overwrite. The difference being that instead of writing over the data once, you do it multiple times, and often you change what is being written with each pass. A popular (but again, ultimately unnecessary) 3-pass overwrite involves first writing 0's over the data, then writing 1's over the data, and then finally writing random 1's and 0's. This is the method used by the DOD, but you only have to Google "DOD 3 pass wipe" and most of the articles are debunking it.
