Erasing CDs By Using 150,000 Volts of Electricity 242
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."
Microwave (Score:3, Informative)
Does a thorough enough job, almost everyone has one on hand, takes but 2 seconds an
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Which is why four 12 gauge shells ought to be just the masochism that a forensic artist was looking for, after a few CDs are lined up in a row for target practice.
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Because someone with patience can piece a shredded item back together again.
Not a CD they can't.
Even if you managed to get all the pieces physically back in the correct positions, it would not be readable.
The error rate would overwhelm the redundancy algorithms.
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If you only wanted a small portion of the data, it would work just fine.
Even a disc with a lot of errors will still read to a extent.
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Except that:
(a) the worst damage will be closest to the spindle, which is where the data write begins.
(b) properly cross-cut into 1/4" or less width, the shattering rate should eliminate better than 90% of the data between strips.
(c) shattered in such a fashion, oxidization will quickly take care of the remaining data. The leaves will separate, exposing the metal data layer to air, and oxidization will set in damn quick (can you, even with "patience", collect it all AND put it all back together correctly in
Re:Microwave (Score:5, Insightful)
Recordable discs use gold or silver with negligable oxidation of the reflector. You might get some level of degradation of the dye and call that "oxidation" but we're talking about the reflector, right?
Manufactured discs use aluminum which does oxidize somewhat. In extreme environments with lots and lots of humidity you can get the aluminum to oxidize but only a very few people have ever actually seen it. Mostly this is a myth started by the folks proclaming "DVD rot" which has only occurred in some really odd circumstances.
The problem with shredded discs being put back together is that it will take the drive about 1/4th of a turn to regain tracking after a break. You are NOT going to be able to align the spiral across a break - wraps of the spiral on a DVD are around 1000 nanometers apart. They are a whopping 1400 nanometers apart on a CD so that might be as much as 40% easier.
Since visible light has a wavelength around 500 nanometers, we are talking about features that cannot be resolved by magnification. You might, and I say just barely might, be able to do this with an electron microscope and some sort of micro-manipulator. Maybe.
Having a piece of a sector doesn't do you any good really. The data isn't encoded as bytes on the disc and there is physical scrambling of the bytes to spread them out. For example, to read one sector on a CD you have to read three. On a DVD it is worse - you have to read 16 of them.
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Recordable discs use gold or silver with negligable oxidation of the reflector. You might get some level of degradation of the dye and call that "oxidation" but we're talking about the reflector, right?
Manufactured discs use aluminum which does oxidize somewhat. In extreme environments with lots and lots of humidity you can get the aluminum to oxidize but only a very few people have ever actually seen it. Mostly this is a myth started by the folks proclaming "DVD rot" which has only occurred in some really
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Re:In The Ghetto, 01-10. (Score:4, Informative)
Github, Reddit,^H^H^H^H^H^H^H Slashdot... the sewer [4chan.org] is overflowing.
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Th
Microwave (Score:5, Insightful)
Science geeks have been doing this for years with microwave ovens; though, it was more for the cool light show than for data security.
First post? (Score:2)
I find that fire works pretty well. (Score:2)
n/t
Heh (Score:2)
150,000 volt transformer? Ah, now the ball’s in Farnsworth’s court. I suppose I could part with one and still be feared.
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However, I wouldn't think of this as a way
Fire? (Score:2)
What, throwing it in fire wouldn't have worked?
Please... (Score:3)
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What's the fun in that?
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Someone not too long ago thought that would work. The US Secret Service broke in on them and from across the room the guy said "You aren't getting this one!" and broke a disc in half.
The Secret Service called us and asked what could they do? We told them a couple of interesting techniques for putting a snapped disc back together and sent them a trial version of our software to assist with the task. An hour later they called back and ordered four copies of the software and never said another word about wh
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I believe it actually states the MOST SECURE in the post.
Which, as well all know, are never wrong and always 100% accurate.
What's wrong with just burning them? Why would someone ever want to waste 150,000 volts to erase a little bit of data on a single disc when you could erase as many as you can toss in for the low, low energy cost of a single burning log?
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What's wrong with just burning them? Why would someone ever want to waste 150,000 volts to erase a little bit of data on a single disc when you could erase as many as you can toss in for the low, low energy cost of a single burning log?
Er, I believe that I'm stating the bleeding obvious here when I say "because it's cool and fun".
Really, did you seriously think the guy was doing it that way for any other reason, or seriously suggesting it as a practical solution to your disk-wiping needs?!!
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You have it backward with regard to the energy cost. You see you have 150 000 V * 0.001mA *25s and for a typical 1kg wood log (assuming total combustion) you have 18 MJ/kg * 1kg and according to wolframalpha [wolframalpha.com] 150000 V * 0.001mA * 25s 18 MJ/kg * 1kg = true
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You forgot to factor in the number of discs destroyed via current (1) versus the number of discs destroyed by the log, and calculating the energy cost to destroy per disc. I'll leave the number of discs that a 1kg burning log can melt as an exercise for the reader.
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I must admit that you are true, you can achieve a more efficient destruction with the log if you scale the process up.
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Its in the metal, otherwise the metal would not be required.
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Nope, the metal is a reflective layer allowing the pits in the plastic to be seen by the laser.
http://electronics.howstuffworks.com/cd1.htm
Depending on this top acrylic layer; it may be that depositing a new metal layer on the top of the disc will allow this to be read again.
CD-R have the data stored in the dye layer, the metal is just a reflective surface
http://computer.howstuffworks.com/cd-burner4.htm
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Isn't the data actually stored in the plastic, rather than the metal?
So wouldn't recovering the data just be a case of putting something reflective on the back of it? e.g., placing a blank CD on top of the erased one.
No. The data is stored on tiny pips and pits in the metal.
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Sandpaper? (Score:2)
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Beat me to it. The important surface on a CD is the "side" with the label on it. A few seconds with sandpaper does very easily solve any issues. Note - with something more complex like a dual-layer DVD, you have to destroy the actual disc to get at the second layer.
Nice (expensive) toy, but destroying CDs is stupidly easy.
That... (Score:4, Insightful)
That... was one of the coolest electricity displays I've seen in a long time.
Ta heck with what it does, lol
-AI
wha? (Score:4, Insightful)
The microwave
A Fire
Paper shredder
Acetone
This is just an expensive toy
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lots of ways to destroy a plastic disc with metallic coating. i kind of agree. there is the relative small risk in shreading that they can somehow reconstruct a disc, but even then they wouldn't have anything near a complete image. nope, i'd say about 3-5 seconds in the microwave is about the quickest and easiest way to nuke a cd.
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A Fire
A friend of mine lost his house in the 2009 brushfires here in Victoria. He had a fantastic and very valuable music collection. After the fire he went back with his partner and looked through the wreckage. They found nothing remotely resembling a CD.
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Finally, something to do with all those junk AOL CDs!
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I use my bare hands. Feels very macho.
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Fire isn't all that great unless you really get the disc up beyond the glass point of polycarbonate, which is around 230C. You can degrade the dye of recordable discs starting at 120F, but that isn't going to assure unreadability.
Turning the disc into a bent, folded mess is OK, but unless you go that far it isn't going to work.
Some folks had a fire and we were called on to evaluate the readability of the discs. Of the 30 or so they sent us, all but two were fine, even one with clear smoke damage to it. T
Oddly complicated (Score:2)
Seems an oddly complicated way to do it. Just put it in the oven at 350 F for a few minutes. (175 C, for the metric users).
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175 C, for the metric users.
Whats the temperature for a fan forced oven? I always get that wrong.
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African or European?
will it blend? (Score:2)
Is this really secure? (Score:5, Interesting)
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That only applies for pressed discs, not writable ones.
Here's an idea (Score:2)
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Lots of easier ways (Score:2)
Flashy but not secure (Score:3)
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.
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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.
Indeed, I can imagine a CD data-recovery player in the future that analyzes non-reflective surfaces with high-resolution lasers or other imaging, just to recover data from aged CDs. Kind of like the laser-based record-players today. And I imagine such a player available at consumer prices.
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This is true for a manufactured CD. The data will be actually encoded using physical bumps. But for recordable CDs which are typically the only type where you care about erasing, the sparks or microwave should do a good job of messing things up.
Most secure (Score:5, Funny)
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Comment removed (Score:3)
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polycarb plastic? (Score:2)
Its polycarb plastic, right? Expose it to a chlorinated solvent and it'll craze and crumble, kinda de-polymerize itself. Breathing the vapors is inadvisable.
Two Words (Score:2)
Toxic vapor ? (Score:2)
I'm no chemistry whiz, but wouldn't this result in a lot of vaporized aluminum in the air ? Doesn't sound so great for the old lungs, no...
Nonsense (Score:2)
Most Secure vs. Good Enough (Score:2)
"...This may be the most secure method to remove data on conventional recordable CDs used in offices."
Sure, this may be "the" most secure method, but there are plenty of other methods that fall easily into the category of "good enough" (microwaves, shredders, even breaking apart by hand). Kudos for the geek factor with all this, but realistically this is a solution without a problem.
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Just watch as I re-extract half of all the data from every CD that the device has ever wiped from what was electroplated back onto the cathode...Secure, my butt!
Star Wars (Score:3)
Media shredder (Score:2)
At my old job we bought a decent cd shredder. I think that pulling data off of hundreds of little bits of CD would be pretty secure.
Better way (Score:3)
Recycling? (Score:2)
Would that help with recycling CDs and single-layer DVDs?
Shredder (Score:2)
Is pretty damned effective since the plastic shatters as it is cut ( unlike paper ). And if that isn't enough for you, burn what is left over a open fire, with some marshmallows.
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Re:Anyone heard of a microwave? (Score:5, Funny)
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Right. That's bad.
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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.
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Besides that nuking them releases a small bit of toxic gas
Yes I wouldn't want that in the same place as my food.
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Best is to simply break the disk up either manually or in a shredder.
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Well this doesn't really "Erase" the data either. The pits are still in the plastic, just apply a new reflective backing and the disk is readable again. Best is to simply break the disk up either manually or in a shredder.
Yeah, that's what I thought as well. Still, let's be honest, it was pretty good fun, as you'd expect from the same guy that brought you the self-destructing washing machine [youtube.com]. (I recognised his voice on this clip straight away, the accent/style/modus-operandi combo is pretty distinctive once you've seen some of his other videos!)
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Uh, no.
For recordable discs, the data is in the dye. Lose the reflector (because of microwaving) and you lose the data. You cannot "reapply" the reflector - the dye is destroyed with the original reflector thus wiping out the data.
For manufactured discs it is true that the data is cast into the polycarbonate. But, you would need to get at it. It is sealed up in a lacquer coating, of which most of that remains. You aren't going to re-coat the polycarbonate with anything left there and by "anything" I me
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You are incorrect on several fronts.
It is not damaging to the microwave, unless you happen to be microwaving explosive blasting caps or something. The Magnetron(Microwave Emitter Piece Thingy) is usually so far away from anything in the chamber that it's impossible for enough charge to build up that it can arc back and cause problems. For example, on the microwave model I routinely take apart to use for parts, there is a metal channel to guide the microwaves from an area behind the keypad over to a 'stirrer
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You are incorrect on several fronts. It is not damaging to the microwave
Then explain why it damaged the microwave. Theories are nice, they have to agree with experiment though.
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Re:For those with less sense and less money (Score:4, Funny)
I have seen lives ruined this way - be careful out there.
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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.
Re:For those with less sense and less money (Score:4, Insightful)
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
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how is anything hard on the magnetron? all it does is emit energy, which the metal readily soaks up and superheats. The real danger is more catching the microwave on fire than anything.
Re:For those with less sense and less money (Score:4, Interesting)
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.
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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.
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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. It
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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.
And this is why I love slashdot.
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However, if you put a continuous loop of metal in there, you can pretty much expect it to arc and possibly explode. It has something to do with forming a current loop, which cannot build up in a flat (
Re:For those with less sense and less money (Score:5, Informative)
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.
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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 damagi
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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 re
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how is anything hard on the magnetron? all it does is emit energy, which the metal readily soaks up and superheats. The real danger is more catching the microwave on fire than anything.
Spoken like one who has never killed a microwave in their day. Its easier than you think. Chances are that its the main circuit board that is actually damaged and not the magnetron itself, but I've killed a couple with no sign of fire. (Lightning in a box, but no smoke and no fire).
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None of this stops someone from going back in time and getting the original.
The only way to secure your data is by not creating it in the first place. THINK, PEOPLE!
Re:For those with less sense and less money (Score:5, Interesting)
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.
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it's easy to damage the microwave if you keep it running for too long, since the CD doesn't contain a whole lot of water
That's why I put the CD over a half-full glass of water when I do it.
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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).
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What's especially amusing is that effect could also be used in that sentence, both in relation to the creation of the "effect" and also "effect" the process - make it possible. Although I think you MEANT affect, he really was very narrow-sighted to grammar-nazi it. He should have instead replied as if you did indeed mean effect.
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it's the amps
And it's not the fall that kills you, it's the sudden stop at the end. Except you don't get that sudden stop without falling. And you don't get current without voltage. It's a cute little saying but it doesn't actually say much.
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