• Welcome to the Off-Topic/Schweb's Lounge

    In addition to the Mac-Forums Community Guidelines, there are a few things you should pay attention to while in The Lounge.

    Lounge Rules
    • If your post belongs in a different forum, please post it there.
    • While this area is for off-topic conversations, that doesn't mean that every conversation will be permitted. The moderators will, at their sole discretion, close or delete any threads which do not serve a beneficial purpose to the community.

    Understand that while The Lounge is here as a place to relax and discuss random topics, that doesn't mean we will allow any topic. Topics which are inflammatory, hurtful, or otherwise clash with our Mac-Forums Community Guidelines will be removed.

Does degaussing still happen?

Joined
Feb 15, 2011
Messages
388
Reaction score
6
Points
18
Location
West Virginia
Your Mac's Specs
13in rMBP 2014 Yosemite
I remember back on my parents Gateway Millennium edition PC the monitor had a degaussing button. Never really had a use for it or understood what that meant until college.
Now I work in radiology and have a more than basic knowledge of MRI units.
I have been wondering-what are the standard ways to wipe clean a hard drive?
I always assumed a drive would be plugged into what ever peripheral it needed and somebody would hit reformat on a home base computer. I come to learn there are certain levels of security- just in OS X we can select an option that will take 15 hours or something to write a zillions zeros on your hard drive. Or just 30 seconds and then it's "empty" again but with out it really being blank.
Wouldn't a very strong magnetic field do the trick much faster and just as "secure"?
The Magnet in my hospital is average at 1.5 or 2.0 tesla. From what Google showed me that's about average for degaussing magnets available for purchase. If you have enough current/amps there isn't really a limit to what people can push through a magnet. Some research hospitals have 10 T magnets. And from an episode of myth busters I think there are magnets up near 45 T
I get that it may not be cost efficient to have a liquid helium super cooled magnet for a business to wipe clean hard drives. But wouldn't it be more efficient time wise?
Sorry for rambling.
 

chscag

Well-known member
Staff member
Admin
Joined
Jan 23, 2008
Messages
65,248
Reaction score
1,833
Points
113
Location
Keller, Texas
Your Mac's Specs
2017 27" iMac, 10.5" iPad Pro, iPhone 8, iPhone 11, iPhone 12 Mini, Numerous iPods, Monterey
For your questioning mind... ;) The US government does not reuse a hard drive once it stored classified data. They first use a wiping routine (similar to what Disk Utility would do), they then degauss, and afterward completely destroy the drive.

The degaussing you referred to above on the "Cow Box" (Gateway) was to remove any magnetism on the surface of the CRT. Older style TV sets likewise had built in degaussing circuitry. Modern LCD displays are not subject to the same magnetic distortion and no longer need to be degaussed.
 
OP
T
Joined
Feb 15, 2011
Messages
388
Reaction score
6
Points
18
Location
West Virginia
Your Mac's Specs
13in rMBP 2014 Yosemite
At least there is something that uses redundancy inside the government that indeed-needs redundancy.
 
Joined
Nov 26, 2012
Messages
1,035
Reaction score
22
Points
38
Location
Agusan del Norte, Philippines
Your Mac's Specs
L2012 Mini, i7 2.6Ghz, 8GB RAM, 256GB SSD + 1TB HDD(fusion), BenQ 32" 2.5k QHD Display
Degaussing removes the magnetic field that a CRT can pickup, basically grounding it out. On pretty much all modern Navy ships the entire ship has a degaussing system to prevent mines from being drawn to the ships hull. Plus other various reasons they likely wouldn't disclose. But when I was in the Navy most of the ships still used CRT monitors and we frequently through out the day would end up having to degauss the display to keep from looking at rainbows.

As far as hard drives I think Chscag meant secret/secure(RED) on those drives, as everything was rated as classified(GREEN). Every classified drive is reused in classified systems. But once it quits working it is then sent stuck to a large magnet and whipped. I think the IT department would even send the secure ones in for further cleansing. At least thats how the Navy did it. We used everything until it physically couldnt be fixed.

As far as data security, there is ways of completely removing data from your drive, but it consist of writting random data bits to the drive in hand many times over and over. I think it was up to 10 times for what the NSA recommends for standard security. IIRC.
 
Joined
Apr 26, 2008
Messages
2,963
Reaction score
120
Points
63
Location
Belgium
Your Mac's Specs
iPad Pro 12.9 latest iOS
Degassing still happens in some organisations.
After that it is usually thrown into an oven and burnt beyond recognition :)

Cheers ... McBie
 

Shop Amazon


Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Top