Windows 7 Forums

Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.


Windows 7: Reformat and secure data deletion

22 Feb 2011   #21
Golden
Microsoft MVP

Windows 7 Ult. x64
 
 

Quote   Quote: Originally Posted by DeaconFrost View Post
it is well worth the extra time to do a DoD wipe, just to be sure. I do them when I sell a disc online or through eBay to someone I don't know. I use a zero-only option when I give a drive to a friend or family member. When I'm dealing with releasing my drives to the wild, I prefer to know for sure that my data is gone. If it takes an extra hour or so, I'm fine with that.
I agree with this approach.

Todays opportunistic criminal looking for financial gain is far more sophisicated than the previous generation. Previously they would be prepared to dig through our trash for paper documentation, today they are happier doing it from the comfort of their workstation running algorithms on a disk they found or were sold. Considering the vast amount of financial information we store on our disks, it seems prudent to be a little bit more careful.

Safe computing,
Golden


My System SpecsSystem Spec
.
22 Feb 2011   #22
FliGi7

XP / Win7 x64 Pro
 
 

Quote   Quote: Originally Posted by DeaconFrost View Post
Quote   Quote: Originally Posted by FliGi7 View Post
All data is unrecoverable after one pass of 0's to the full drive. Doing more passes than one is superfluous.
If seen plenty of people suggesting otherwise. I don't know enough to say which is right, but considering what a person has to lose, it is well worth the extra time to do a DoD wipe, just to be sure. I do them when I sell a disc online or through eBay to someone I don't know. I use a zero-only option when I give a drive to a friend or family member. When I'm dealing with releasing my drives to the wild, I prefer to know for sure that my data is gone. If it takes an extra hour or so, I'm fine with that.
I happen to know about this in particular and one pass will render all data unrecoverable. Even an STM, as Monsoon mentions, will not be able to recover it. Any empirical tests that have been done have only been able to "recover" data that they knew was there before-hand (i.e. they were able to deduce from circumstantial evidence that a 1 was there prior to the wipe by knowing it was there before-hand). The reasoning behind any testing for recoverable data boils down to the fact that 1's are never 1.00000 and zero's are never 0.00000 on disk.

At any rate, there has never been a case of substantial (more than finding a possibly conclusive remnant one or zero) data recovery via STM after even one pass of zero's. Two or more passes is for the mental benefit, not actual.
My System SpecsSystem Spec
22 Feb 2011   #23
Golden
Microsoft MVP

Windows 7 Ult. x64
 
 

Hi Fligi7,

If that is the case, what are the origins and reasoning behind such methods as the Gutmann 35 Pass method?

Regards,
Golden
My System SpecsSystem Spec
.

22 Feb 2011   #24
ignatzatsonic

Microsoft Community Contributor Award Recipient

Windows 7 SP1, Home Premium, 64-bit
 
 

Quote   Quote: Originally Posted by Golden View Post
Hi Fligi7,

If that is the case, what are the origins and reasoning behind such methods as the Gutmann 35 Pass method?

Regards,
Golden


My guess would be paranoia. It's got a lot to answer for.
My System SpecsSystem Spec
22 Feb 2011   #25
FliGi7

XP / Win7 x64 Pro
 
 

Quote   Quote: Originally Posted by Golden View Post
Hi Fligi7,

If that is the case, what are the origins and reasoning behind such methods as the Gutmann 35 Pass method?

Regards,
Golden
That was a technology developed in 1996 on older, much less dense drives where variances in permittivity were much more evident and plausible for data recovery. Soon thereafter as time progressed and hard drives became more and more dense, these nuances were essentially rendered obsolete and it was deduced that 35 passes never needed to be done, rather a couple (at most) random data passes would provide the same data recovery safety.
My System SpecsSystem Spec
22 Feb 2011   #26
Golden
Microsoft MVP

Windows 7 Ult. x64
 
 

Thanks Fligi7. So would it be true to say that a lot of the software that contain multiple algorithms like DoD 5520, Schneider 7 Pass, Gutmann etc. are/may be obsolete?

If I understand you correctly, 2 writes (1 x 0, 1 x random?) are sufficient on modern day hard disks?

Regards,
Golden
My System SpecsSystem Spec
22 Feb 2011   #27
FliGi7

XP / Win7 x64 Pro
 
 

They're not obsolete methods, just overkill for the goal of secure data deletion in 99.99% of cases.

For all intents and purposes of the consumer getting rid of a hard drive or selling it, one write of 0's is sufficient enough to prevent data recovery. It might be possible for someone with a Scanning Tunneling Microscope to recover bits and pieces of the data if they have the time and resources. This somewhat empirical, although not very productive or substantial, ability for recovery is what drives entities with much higher stakes in the data to use multiple passes to further prevent any possibility of it. But, we're talking reducing the possibility from near zero to even nearer to zero.
My System SpecsSystem Spec
22 Feb 2011   #28
Golden
Microsoft MVP

Windows 7 Ult. x64
 
 

Thanks. That was very enlightening.
My System SpecsSystem Spec
22 Feb 2011   #29
FliGi7

XP / Win7 x64 Pro
 
 

Sure thing. Sometimes it just makes more sense to kill two birds with one stone and take some aggression out by using the sledgehammer method.
My System SpecsSystem Spec
Reply

 Reformat and secure data deletion




Thread Tools





Similar help and support threads
Thread Forum
Help requested / needed to secure data on a public network
Hello there Seven Forums, I used to work in a Home Network situation supported by a Router, but now I am on a Private Network in an office block that I share with many others. I have a networked desktop PC called G79, and a networked Laptop called G81 that serves as my server for all of my...
Network & Sharing
Data in the Cloud cannot be guaranteed to be secure
Hi everyone While This news snippet concerns a slightly different topic but : You can see what *Could* happen if the people who own the servers have legal problems with content. http://www.bbc.co.uk/news/technology-16787486 -- users could be prevented from gaining access to...
News
Need help with reformat without losing data
Hello, I have a problem I know I will run into when I build my new computer. Before I moved I only took my hard drives with me because I thought I could just buy a new computer and put my HDDs into that computer. But it seems like that it may not boot at all, although it depends on my luck. ...
Backup and Restore
data recovery + deletion
Hi everyone, I want to donate my old laptop but there are several documents that have been deleted in the past but can easily be recoverd. When I run 'restore deleted files' (from TuneUp Utilities) to recover those documents and delete them thoroughly the recovered documents stay on the HDD....
Software
Best way to secure large amounts of data?
I have a 2TB hard drive which I bought to back up my DVD collection. At the time I thought I would never fill it, but at this point it is almost full and I can easily see myself filling another one some time in the future. I plan on adding another 2TB drive and putting them in RAID to appear as...
Music, Pictures & Video

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 06:46.

Twitter Facebook Google+



Windows 7 Forums

Seven Forums Android App Seven Forums IOS App