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Erasing CDs By Using 150,000 Volts of Electricity
ryzvonusef writes "One enterprising individual has created the most secure way to wipe out Compact Discs, by using a step-up transformer and creating a 150,000 Volt pd, whilst a CD rotates in the middle. The sparks arc through the metal in the CD and evaporates it, ripping it all off as the CD rotates. The CD is rendered transparent and unreadable. This may be the most secure method to remove data on conventional recordable CDs used in offices."
Does a thorough enough job, almost everyone has one on hand, takes but 2 seconds an
Science geeks have been doing this for years with microwave ovens; though, it was more for the cool light show than for data security.
Just break the damn things.
I'm not anti-social, I'm anti-idiot.
Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.
actually the foil is VERY quickly shattered, it's quite spectacular and is a good deal safer on the magnetron than the other article today where someone was suggesting microwaving a hard drive
I work for the Department of Redundancy Department.
That... was one of the coolest electricity displays I've seen in a long time.
Ta heck with what it does, lol
-AI
For me, it is far better to grasp the Universe as it really is than to persist in delusion
Most secure? My ass...
The microwave
A Fire
Paper shredder
Acetone
This is just an expensive toy
I've done it dozens of times. My 13-year-old cheapo microwave oven didn't bat a lid. Still going strong.
I think the "easy to damage the microwave" is an urban legend. Someone should submit it to Mythbusters.
I hadn't known there were so many idiots in the world until I started using the Internet -Stanislaw Lem
This can^H^H^H will destroy a microwave ... not that I know or anything ... it was "my friends" microwave. Besides that nuking them releases a small bit of toxic gas and it is not 100% effective to erase all the data.
Just get a DVD Shredder .. save your microwave, save yourself .. and most importantly you^H^H^H "your friend" will have a microwave to nuke those pizza roles at 11 pm at night.
-- Knowing too much can get you killed, but knowing who knows too much can make you rich.
Of course you can not read a CD if the reflective metal layer is removed. But the data is stored in tiny pits that are printed into the polycarbonate layer. If the polycarbonate is not damaged too much, the CD might be readable when a new metal layer is applied.
The metallic reflective layer is NOT where the information is stored, it just aids in the information retrieval. In other words, this method might not destroy the data at all. It's true that it's pretty hard to get the data back, but depending on various conditions it may not be impossible.
Did you know that "FTW" ("for the win") is a direct translation of "Sieg Heil"?
The most secure way to destroy CDs is either dissolving in acid or loaning them to my boss. I promise, you'd never see it again.
Just give it to a three year old to play with for a while. Even the NSA wouldn't be able to get any data off of it!
It's very easy to damage the microwave when doing so.
Buy a cheap microwave just for this purpose. I'm guessing a 150,000 volt transformer is going to cost you more than $70 (and probably weigh a bit more than a small microwave too).
Skeet Shoot
The thinking goes, the magnetron is basically an antenna, right? So it can pick up as well as transmit energy. If an electric charge builds up and arcs stright into the magnetron, it can blow up. Or something like that. I've never seen it happen, and I've blown up a lot of stuff in microwaves over the years.
A quick google search for "blow up the magnetron" turned up this answer from a microwave engineer:
2. metals in the microwave oven - they will not destroy the oven or cause it to blow up. I routinely heat my coffee with a spoon in the cup. I also did the definitive early research on this in the late 70's and early 80's. But it is possible for metals to arc (spark) under certain conditions. This can be dangerous especially with things like metal twist ties and steel wool. Also, things like the metal trim (silver or gold) around the rims of fine china is dangerous in that the dish or cup can easily beak or shatter - but this due to the trim not being perfectly continuous like a wire that would carry current, Instead the trim has microscopic gaps and that can cause micro-arcs and temperatures exceeding 1000 F locally.
Don't you just love the Internet? We get to be wrong more often, but not for as long.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
I've used one of these for years in a SCIF. http://www.whitakerbrothers.com/datastroyer-101-cd-high-security-shredder
Is it only me or does this remind some of the Emperor's line, "Now you will witness the full power of the Dark Side!"
It's not an intuitive thing, don't worry you're not alone in not immediately seeing the problem.
A magnetron is a kind of RF (radio frequency) transmitter. It converts electrical energy into radio energy. This energy leaves the magnetron and bounces around inside the microwave. The frequency used makes it tend to interact with water molecules, and heats them up, changing radio energy into heat energy. And that's what heats the food. (note that foods with significant water content heat best)
The microwave is tuned just like an antenna is tuned, to maximize the use of energy. Energy the magnetron takes from electricity has to go somewhere. Energy sent into the box that isn't absorbed and converted to heat is reflected back to the transmitter. This is aka a "standing wave". The "Standing Wave Ratio" tells how efficient the energy transfer is.
A high SWR means a large percentage of the input energy is being reflected, and back to the transmitter where it must be used and so is converted into heat. Transmitters expect some of this because the conversion isn't perfect to begin with, but they're not designed to handle a LOT of additional energy to dump, and will overheat. Very high frequencies like magnetrons use are especially inefficient to start with, and so they're usually designed to cool heavily, with fans and fins. The heat you feel coming out the back of the microwave is NOT heat from the food, it's the waste heat off the magnetron. Adding too much to that waste heat can overheat and damage the magnetron, sometimes very quickly.
So, if you put a substantial chunk of metal into a tuned cavity like a microwave oven, it will interfere with the transfer of energy and cause a higher SWR, which can damage the magnetron. Running a microwave without anything in it is not recommended for the above reason, but adding metal into the mix makes matters worse. Placing nothing in the cavity besides a substantial piece of metal is about as destructive as you can be. The denser the metal, the bigger the effect.
I work for the Department of Redundancy Department.
Metal isn't always bad in the microwave and certainly won't blow it up. Many modern microwave food containers have a metal grid in them to diffuse the microwaves as they cook the food.
Although the vaporized foil probably isn't good to breathe or eat.
Github, Reddit,^H^H^H^H^H^H^H Slashdot... the sewer is overflowing.
To understand recursion, you must first understand recursion.
No, it's not like in the movies, they don't "blow up". They can fry the magnetron or the support electronics, or make a little lightning inside the food compartment. Might smoke a bit, or at best make a nice sparky energetic POP.
And close on the grid but not quite, I was going to mention this in my last post but forgot, newer microwaves all have a vaned fan blade looking affair in them that is in the line of fire in the box. It's often doing double duty as a cooling fan for the food or the magnetron. Its blades are moving, and cause the RF energy to reflect around in a non fixed pattern inside the box (which IS lined with a metal grid), this allows the microwave to heat the food more evenly.
It's like tossing a handball in a handball court, how the ball bounces around depends on where you're standing and what direction you throw. If you throw the same way each time, the ball will travel through the room in the same routes every throw, and there will be places in the room that the ball never gets near. Now imagine I place an exposed fan in the room and you're throwing at the fan every time. Depending on the position of the blade that ball could go almost anywhere. Same thing applies with microwaves. The handball represents the RF energy the magnetron is throwing out.
I work for the Department of Redundancy Department.
Plasma gasification, after a few seconds at 14,000C, there is not much left. Even works with BluRay(R), and you do not have to pay Sony.
Mod parent up.
It's also not the metal in the oven that's bad for it, it's any configuration where the microwave energy is not absorbed. Metal can absorb (well, couple to, or "receive") microwave energy just fine if it's the right length (this is why the sliced grape plasma thing works too). You can solder a couple short wires onto the end of an incandescent lightbulb, making a little 1/4 wave dipole antenna at 2.45GHz, and the bulb will light up in the oven.
Traditionally the *worst* configuration for damaging the oven is to run it EMPTY (or at least with nothing in it that can absorb the energy). This results in a nearly infinite SWR, with almost all the 600-1200W of energy getting "reflected" back at the transmitter, and it will heat up and die (or melt something important nearby) within maybe 10-30 minutes or so.
Same thing will happen to most transmitters if you disconnect the antenna creating a huge impedance mismatch that literally reflects the energy back to the transmitter. And it's the same reason all high speed communication links (Coax Ethernet, SCSI, etc.) have "terminators" to sink the energy at the end of the transmission line so it doesn't bounce off the end of the cable and echo back down the line.
Metal in the oven is *usually* not a problem the way people think it is. But it will block and reflect (in a more traditional sense) the energy around so that you can't cook a potato wrapped in foil.
Modernist Cuisine has this to say: "Myth: You can't put metal in a Microwave. Fact: Microwaves already have plenty of metal in them: the walls of the oven, the fan [that distributes the microwaves], and so on are all metal! What you need to be careful of is metal that has sharp points or edges. Those features concentrate the electrical field in the oven and cause arcing. Arcing in and of itself isn't too dangerous, but it can ignite dry flammables in the oven. The reason to not use metal cookware is that microwaves cannot penetrate the metal, so your food will not cook."
G.
You need to put a cup of water in with the disc. Failure to do this can screw up the magnatron tube and ruin the microwave oven. 3 to 5 seconds is the limit - you can get flames for much longer than that and burning polycarbonate isn't good for anyone.
There is no "toxic gas" other than burning polycarbonate.
I have students that build tesla coils for extra credit projects every year or two, and have built one myself just for the fun of the big sparks. They generate ballpark of 150 kV at the top, and putting a CD on top so that you could watch the lightning arc out of it and craze the plastic and underlying metal was great fun. Naturally, at that voltage the plastic isn't exactly an insulator, so you get fractal lightning patterns almost instantly through the metal.
However, I wouldn't think of this as a way of technically erasing all of the data -- not erasing as in not all of the king's horses nor all of the kings men using NSA's resources can put it together again erasing. Erasing as in nobody is going to be able to put it in a stock player and scan any data off of it perhaps, but removing all of the actual physical encoding of the medium so that people cannot read off local patterns of information and apply information theoretic analysis to POSSIBLY reconstruct chunks of it? I don't think so. I'm not even sure that I'd trust scrambling or oxidizing all of the metal for that -- the plastic alone might contain enough structural alteration that a very sensitive molecular-level scan could pick up patterns, if you have a few tens of millions of dollars to use trying (NSA money, in other words).
But simply breaking a CD or DVD in two is probably enough to stop all but the most dedicated and well-equipped would-be data thief. There would have to be a strong incentive to spend real money to reconstruct even that.
With that said, I agree with the individual above who said fire. Fire takes care of all of the information, whether it is cooking in a microwave or conventional oven or in a real fire with real wood outdoors. Because of the toxins given off by burning plastic, I like outdoors. Not even the NSA could reconstruct information from DVD ash, or even (realistically) from the blob of molten plastic you'd get even before you turned the DVD to ash and then blew the ash into the air as a fine powder or washed it into the dirt. Fire is raw entropy.
rgb
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
Yep.
Which is why, when I nuke strange things in the microwave, I keep a cup of water in there as well (along with something wooden in it to act as a nucleation point to start it boiling). It soaks up energy that might otherwise find its way back to the magnetron.
Is it perfect? No. But it is good enough, in my experience: I've had the same microwave for 8 years, and it works just as poorly now as it did when it was new.
There is, of course, the odd chance that the thing I'm nuking will form a nice neat reflector and send a significant portion of the magnetron's energy back into itself before it can be converted to heat by the water. And standing waves, as you rightly describe, can be even worse.
But the revolving platter (or stirrer, in other models) will keep the duration of this reflection down to a very short duration, while also keeping the standing waves moving instead of possibly forming a particularly destructive, static pattern.
Unless I make a retroreflector out of metal and microwave that. Hmm....
Kid-proof tablet..
I have seen lives ruined this way - be careful out there.
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