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Standard User camieabz
(sensei) Wed 25-Apr-12 09:58:20
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Data on old hard drives


[link to this post]
 
http://www.bbc.co.uk/news/technology-17827562

Watchdog finds undeleted data on second-hand disk drives


Of the 200 hard disks collected, 11% contained personal information.

At least two of the drives had enough information to enable someone to steal the former owners' identities, the watchdog said.


I'm slightly peturbed at that statistic. Why didn't they say three drives or the actual amount? "At least two" is a strange way of putting it when dealing with whole numbers.

Equally they didn't add that many buyers of second hand drives are not looking for peoples' data, however, the article might encourage some to start looking or worse, start buying to get data.

Lastly the Beeb article doesn't give advice on how to delete sensitive data from their drives. Here are a couple of free and easy methods:

1) If just throwing the drive out, delete data, format drive, then take it apart and smash the disc(s) with a hammer. Best to do this in an area where it can catch all the shards of glass. Data definitely gone!

2) If selling on, delete the data, and copy useless data to the drive until full. Download a large file and copy it or copy the copies. delete data with a free drive wiper program, such as the one which comes with CCleaner. Then format the drive. Data gone!

Personally, I never sell on my HDDs, so I use option 1, but also do the files and CCleaner bit too. Overkill is impossible when dealing with your data.

~ Camieabz ~

All Connection Data ~ plusnet

mod'er·a'tion n.
Synonyms: temperance, restraint, modesty.

Edited by camieabz (Wed 25-Apr-12 11:37:41)

Standard User 4M2
(experienced) Wed 25-Apr-12 10:57:27
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Re: Data on old hard drives


[re: camieabz] [link to this post]
 
Yep, even overwritten files can be retrieved - best to do a full reformat or if the drive is not working smash the disc with a hammer!
Standard User john2007
(legend) Wed 25-Apr-12 13:12:22
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Re: Data on old hard drives


[re: 4M2] [link to this post]
 
In reply to a post by 4M2:
Yep, even overwritten files can be retrieved ...

By who? I thought this had the status of an urban myth.


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Standard User micksharpe
(eat-sleep-adslguide) Wed 25-Apr-12 13:29:49
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Re: Data on old hard drives


[re: john2007] [link to this post]
 
In reply to a post by john2007:
In reply to a post by 4M2:
Yep, even overwritten files can be retrieved ...

By who? I thought this had the status of an urban myth.
It is possible but the techniques used are time-consuming and require specialist equipment. At the most extreme, magnetic ink can be applied to recording surfaces and the patterns read using a microscope.

“If you limit your choices only to what seems possible or reasonable, you disconnect yourself from what you truly want, and all that is left is compromise” - Robert Fritz
.
It Ought to be Easy | Greasemonkey scripts
Standard User gomezz
(eat-sleep-adslguide) Wed 25-Apr-12 13:55:28
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Re: Data on old hard drives


[re: micksharpe] [link to this post]
 
With today's paranoid government agencies the very act of physically smashing a hard drive to prevent data recovery is enough to invite their closest scrutiny. frown

O2 Standard (8Mbps LLU)
Standard User camieabz
(sensei) Wed 25-Apr-12 14:37:21
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Re: Data on old hard drives


[re: gomezz] [link to this post]
 
If the police or said agencies were forcing an entry to a property and discovered someone in the act of doing that, fair enough. Otherwise, it's a sensible precaution. No different to shredding sensitive mail.

~ Camieabz ~

All Connection Data ~ plusnet

mod'er·a'tion n.
Synonyms: temperance, restraint, modesty.
Standard User john2007
(legend) Wed 25-Apr-12 14:44:00
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Re: Data on old hard drives


[re: micksharpe] [link to this post]
 
http://en.wikipedia.org/wiki/Data_recovery (section titled overwritten data).

SSDs may be more of a risk.
Standard User Deadbeat
(knowledge is power) Wed 25-Apr-12 15:09:15
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Re: Data on old hard drives


[re: camieabz] [link to this post]
 
Most of the used drives that I come across have all the data fully intact. What surprises me is that the percentage is as low as it is!
Standard User micksharpe
(eat-sleep-adslguide) Wed 25-Apr-12 15:48:27
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Re: Data on old hard drives


[re: john2007] [link to this post]
 
My info is several decades old. I used to know someone who made colloidal magnetic suspensions for researchers and forensic organisations. Of course, magnetic force microscopes weren't invented then and the amount of data recorded on disk drives was miniscule compared with today's devices.

I've only given the article a quick scan but it does not seem to mention bad blocks that have been reassigned by a device's internal firmware. These will be invisible to standard software but will be visible to specialist hardware and may contain useful information.

The best security practices are (1) use of drive encryption in case of theft and (2) use of a sledgehammer prior to disposal.

“If you limit your choices only to what seems possible or reasonable, you disconnect yourself from what you truly want, and all that is left is compromise” - Robert Fritz
.
It Ought to be Easy | Greasemonkey scripts

Edited by micksharpe (Wed 25-Apr-12 15:50:03)

Moderator billford
(moderator) Wed 25-Apr-12 16:29:55
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Re: Data on old hard drives


[re: john2007] [link to this post]
 
In reply to a post by john2007:
In reply to a post by 4M2:
Yep, even overwritten files can be retrieved ...

By who? I thought this had the status of an urban myth.
It can be done if you're really determined, but as Mick said it's expensive and time-consuming.

But if the data is worth it... when we had to dispose of classified HDDs at Aldermaston, they were stripped down and the magnetic coating sandblasted off the platters.

edit- and two witnesses had to sign off that it had been done properly!

Bill
bill@thinkbroadband.com __________________Planes and Boats and ... __________________BQM

Edited by billford (Wed 25-Apr-12 16:35:36)

The author of the above post is a thinkbroadband moderator but it does not constitute an official statement on behalf of thinkbroadband.
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