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Hardware Hacking Input Devices The Almighty Buck Build

Optical Mice Used To Detect Counterfeit Coins 123

JimXugle writes "El Mundo reports that Spanish researchers at The University of Lleida have used a modified optical mouse to detect counterfeit €2 coins (Original article, in Spanish) with a success rate comparable to that of an expert trained to do so. Details are to be published freely in the journal Sensors."
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Optical Mice Used To Detect Counterfeit Coins

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  • by Monkeedude1212 ( 1560403 ) on Monday November 16, 2009 @05:02PM (#30122442) Journal

    The laser from the mouse will heat up the chocolate inside of counterfeit coins, thus exposing the fakes and creating a mess.

    • Re: (Score:3, Insightful)

      And that's why Spain will never get to host the world Dreidel championships.

    • Optical mouse LED != laser...that was pretty damn funny, regardless
      • Re: (Score:2, Funny)

        by Anonymous Coward

        My mouse has a laser diode.

        Newer Mac mice are cybernetic, touch sensitive because it has a real piece of scrotum skin stretched over the surface.

        • Newer Mac mice are cybernetic, touch sensitive because it has a real piece of scrotum skin stretched over the surface.

          Mmmm, my mouse has only one ball.

          • Mmmm, my mouse has only one ball.

            I call Godwin!

            - Hitler has only got one ball ;
            Goering has two, but very small.

            - Your mouse has only one ball.

            - Therefore, your mouse is Hitler, and you've been a Hitler-massaging Nazi Party member for a significant time.

            - Q.E.D. Civilised argument is over and we can get down to the rioting. Pass me the Molotov Cocktail.

            No, you fool, the unlit one.

    • by hoytak ( 1148181 )

      I read your comment and laughed hard enough to sneeze snot all over my lunch. Now I'm going to go get some chocolate to make it okay. Fortunately, it's not counterfeit.

    • Re: (Score:3, Funny)

      by zoney_ie ( 740061 )

      A real mouse works for that too - they'll happily gnaw through the metallic shell to get at the tasty chocolate inside.

  • by davidwr ( 791652 ) on Monday November 16, 2009 @05:03PM (#30122470) Homepage Journal

    Geesh, can you get me a mouse that detects North Korean bogus US$100 bills?

    • by von_rick ( 944421 ) on Monday November 16, 2009 @05:06PM (#30122534) Homepage
      I can get you a mouse, but you will need to write the algorithm yourself.
    • Hey, it costs me only €1.80 to produce each one. You realise there's a recession going on, right?

    • Does it matter? As long as no one else can detect them they're effectively good money.
    • Printing money is Mafia

      Minting coins _and_ printing money is Maciavellian.

      Just how much Gold and Silver is inside the gravity well of earth?

      I think the economists/bankers/politcos are hiding something that makes a big crashing noise in the Dark.

    • by xaxa ( 988988 ) on Monday November 16, 2009 @07:04PM (#30123946)

      I don't know about €2 coins, but loads of £1 coins are counterfeit -- perhaps 5% [greenend.org.uk]. The €2 (and 1) are bi-metallic though, so presumably harder to fake.

      Under UK law (as that page explains), once you know a coin is counterfeit it's illegal to give it to anyone (except the police) or to keep it. Daft, but it means it's in my interest not to identify counterfeits. (Unless, possibly, I checked every time I was given change. But that's not realistic.)

      • It is fairly "easy" to pass off a variety of Egyptian currency as euros - while certainly something to be avoided, the 2 euro coin is very similar to an egyptian coin of ... I think... 30 euro cents value. I am not quite sure why anyone would want to go about counterfeiting anything of such low value unless they wanted to get their coke machine cokes for 30 cents as opposed to 1-2 euro. Add on the cost of getting caught and thrown in prison on whatever the European equivalent of felony charges is and...
    • Why would you want to detect counterfeit coins/bills anyways? So long as the next person takes them it doesn't really matter. Yes, if we get trillions of counterfeit notes and coins it might start being a problem, but if I can exchange a fake $100 bill for $100 worth in merchandise, it isn't to my advantage to even care if they are real or not. The problem is if you are conned by an obvious fake that the next person won't take, thus leaving you short how much cash you accepted in counterfeit money.
  • by istartedi ( 132515 ) on Monday November 16, 2009 @05:10PM (#30122588) Journal

    In what ways does it defer, if any, from the techniques used in vending machines?

    If it's better, patent and sell to vending companies? Yeah... patents are evil; but maybe a novel application of an existing technology isn't so evil in this case--provided it really is novel and not just a poor-man's vending machine detector, in which case the vending machine companies may already have a patent on it...

    • Re: (Score:3, Interesting)

      by von_rick ( 944421 )
      The corollary to this mouse-hack is that you can use your mouse as a scanner and coupled with an OCR program, use it for getting scribbled notes uploaded to your computer.
      • by Ibiwan ( 763664 )
        I've got a great algorithm for scanning notes with the sensor from an optical mouse; the only thing I can't figure out is how to make sure the mouse knows where it is on the paper...
        • The way they do it at Paper IQ [paperiq.com] is by having an IR ink printed pattern on the paper, which the pen (mouse in your case) can pick up.
        • Use motors and a microprocessor to move it instead of your hand, and an algorithm to detect the edge of the page.
        • by tlhIngan ( 30335 )

          I've got a great algorithm for scanning notes with the sensor from an optical mouse; the only thing I can't figure out is how to make sure the mouse knows where it is on the paper...

          Actually, you know accurately movement, you're just missing a starting point.

          So the simple answer is to assume a square piece of paper whose edge is 2 bills wide - and start at the center. Then you can scan in any bill, regardless of whether it was portrait, landscape, or what corner they started scanning at. Assume that's your

    • Re: (Score:3, Informative)

      Vending machines rely on mechanical factors, mostly: Weight, size, metallic composition (measured by conductivity characteristics).

      This one seems to focus on the graphics on the faces. It's complementary.

    • by BKX ( 5066 ) on Monday November 16, 2009 @05:48PM (#30123080) Journal

      Vending machine detectors are usually just magnets (at least in the US). Very few countries make their coins with enough iron, nickel, or cobalt to be magnetic, so a magnet can pick out most slugs (the usual form of counterfeiting used on vending machines). I know; I own vending machines.

      Also, it's OT, but your sig annoys the crap out of me. I use whom correctly all the time, "intensive purposes" is retarded. Begging the question, though, seems to have actually changed meanings over the years, so, being a descriptivist, I'll give you that one.

      • by Drishmung ( 458368 ) on Monday November 16, 2009 @06:19PM (#30123484)
        Are they just magnets?

        My understanding was that the coin falls into a balanced cradle that measures the diameter and weight. If it's the wrong size it is rejected (and can fall through to another cradle that tests for a different value coin---and so on). If it is the right size but the wrong weight the cradle tips too far or not far enough and deposits it in the reject slot.

        If it's the right size and weight then the coin drops between two magnets onto a little anvil. If the metallic composition is right the coin will slow just enough passing through the magnets to hit the anvil at the right place and speed to bounce into the accept slot. Anything else and it misses.

        The end result is a very quick, accurate but cheap analysis of the coin's weight, size and metallic composition.

        I know that's the way it used to work. Have they dumbed down the machines recently?

        • Re: (Score:3, Informative)

          Back in the 90's I worked for a company that built coin changers and acceptors. Even back then they were using a more advanced method than the one you describe. The acceptor was actually the part that determined what type of coin was inserted and would reject it if it was a slug. The acceptor worked on the same principle as a metal detector. Since coins are made up of a unique mix of metals the acceptors could be "tuned" to accept a certain coin by dropping versions of that kind from different years and dif
          • Back in the 90's I worked for a company that built coin changers and acceptors. Even back then they were using a more advanced method than the one you describe. The acceptor was actually the part that determined what type of coin was inserted and would reject it if it was a slug. The acceptor worked on the same principle as a metal detector. Since coins are made up of a unique mix of metals the acceptors could be "tuned" to accept a certain coin by dropping versions of that kind from different years and dif
            • by jnork ( 1307843 )

              I once was present (1990s) when a colleague dropped a silver quarter into a vending machine. I immediately recognized the sound as the quarter was tossed into the rejected coin bin and traded it for a clad quarter.

              Unfortunately my modest collection of silver coins and a few silver certificates was stolen. What's really irritating is the thieves probably didn't even recognize their value, and I expect just spent them as cash.

              Then again perhaps I should be glad they didn't profit more than they did, and event

              • by sFurbo ( 1361249 )
                The danish mint make a point out of making a lot of special 20 DKK coins (about 4 $), enough that they want get snatched up (I think it is typically 1 million of each, in a population of 5 million). They do this to make it possible to find that (not so) rare treat every time you get money back. Whenever I find one, I eagerly use it, to make sure more people will find one :-) It's not like they will ever be valuable, there are simply to many made.
          • Yes, that would make sense. I'm remembering an article I read in an old Popular Science in my childhood, and more sophisticated techniques 'upcoming' were described then, including the metal detector.

            I couldn't see how "just magnets" (as described in the comment I replied to) would work if only because there needs to be some way to sort by coin type. Every vending machine I use figures out the value of the coins I've fed it.

        • by bitt3n ( 941736 )

          I know that's the way it used to work. Have they dumbed down the machines recently?

          yes, as a result of the 'no vending machine left behind' policy, all vending machines now house a child left behind by the no child left behind policy, who bites each coin between his teeth to test its authenticity.

      • by xaxa ( 988988 )

        Vending machine detectors are usually just magnets (at least in the US). Very few countries make their coins with enough iron, nickel, or cobalt to be magnetic

        Now all the British machines that don't accept 1p or 2p coins make sense! Thanks. (These coins are copper plated steel.)

        the usual form of counterfeiting used on vending machines

        Before the introduction of the Euro replaced 16 different sets of coins with one, a popular method in Europe was to put a low value foreign coins in a machine that recognised it as a higher value. IIRC old British 5p coins would be recognised in Germany as 1DM.

        • by base3 ( 539820 )
          And the U.S. five cent coin was taken by coin acceptors in the U.K. as a 20 pence coin.
      • Also, it's OT, but your sig annoys the crap out of me. I use whom correctly all the time, "intensive purposes" is retarded. Begging the question, though,

        A successful sig, I believe. You do know it was a deliberate troll, don't you? Or perhaps just a gentle stir (don't mod him down for that folks, it's humour). People who can't recognise the humour of deliberate mistakes have never read a book to a child (oh, the glee with which they correct you!) and that's a situation for whomever up with which I can certainly put.

      • Re: (Score:3, Interesting)

        by Valdez ( 125966 )

        For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares?"

        "intensive purposes" is retarded

        Perhaps the poster was going for "for all intents and purposes"?

        If so, ouch.

      • by Alioth ( 221270 )

        I think you need to recalibrate your humour/sarcasm detector on the subject of the parent poster's sig. It's obvious it's a joke.

        Sarchasm: The gulf between the teller of sarcastic wit and the person who doesn't get it.

    • Patents are good, software patents are evil (and invalid in the EU)! This is mostly software so they can bottle up the code and sell it, but if the hardware is interesting enough (it;s not really using a standard mouse), they could patent that.

    • For all intents and purposes, I consider your signature invalid.
    • It's not "for all intensive purposes". It's "for all ant, ents, and porpoises." Get it right next time, OK?

  • Fun fact #65 (Score:4, Informative)

    by dvh.tosomja ( 1235032 ) on Monday November 16, 2009 @05:42PM (#30122998)

    Did you know that there are more than 260 different euro coins from 19 countries to present day!

    • Let us imagine creating an obviously fake denomination, say the 2.50 Euro coin, and try seeing if anyone will call them on it.

      We could make all sorts of fake (Not counterfeit) coins each one of "logical" but otherwise bogus coins, and start using them.

      Of course, one would have to NOT actually complete the purchase with those coins or be subject to arrest for fraud (or similar charges).

      • Re: (Score:1, Interesting)

        by Anonymous Coward

        Some one did something similar in the states several years ago. They made $200 bill with President Bush's portrait and bought some ice cream at dairy queen accepting the change. Don't know if they were ever found but this person was http://money.cnn.com/2004/09/02/news/funny/200_bill/ and I found several other stories while finding that link so yes people would accept them, unless your average cashier in Europe is smarter than over here. Admittedly not a difficult task. On the other side of the coin w

      • by xaxa ( 988988 )

        The only denominations for Euro coins are €0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1 and 2 -- eight different coins. All e.g. €1 coins look the same on one side (a map of Europe), but have different national sides -- an eagle for Germany, a harp for Ireland, etc.

      • Just leave them on the sidewalk. Someone will pick it up and either get a laugh, or be the laugh.

      • by sFurbo ( 1361249 )
        Just making them is probably illegal, even if you can prove you had no intention of using them. It is in Denmark, at least, but we don't use euros.
    • Every year here in Canada we mint a 50-cent coin. I almost never see one outside of a collector's set, however. In fact, it's so unusual to see one in circulation I've seen cashiers refuse to believe they are real money.

      Ironically, US coins are widely accepted in Canada. There are so many US pennies in any random pile of "Canadian" pennies that no one could be bothered to sort them out.

      Also, although US dollars trade for more than Canadian dollars, it's not possible to obtain an exchange rate for coinage. T

      • Ironically, US coins are widely accepted in Canada.

        Whats ironic about it?

        • Re: (Score:3, Interesting)

          by nuckfuts ( 690967 )

          We have a coin of our own that is not always accepted, whereas we readily accept US (foreign) coins.

          You don't see the irony in that?

        • Ironically, US coins are widely accepted in Canada.

          Whats ironic about it?

          That Canadian legal tender is refused by cashiers (i.e. the 50-cent coin), yet foreign coins are accepted.

    • There are not 260 'different' coins. Each state just changes the picture of the coins (except 1€ coin), but coins are still made the same way, materials, size, weight are equal in each country. That leaves just with 8 different coins if my memory doesn't fail me... 1,2,5,10,20 and 50 cents and 1 and 2€...
    • Well, the original members (plus maybe one or two others) produced a set of 8 coins each. Then after the EU expanded, eventually the common design was changed to not only show EU, but all of Europe on the 10c, 20c, 50c, E1 and E2 coins. Some of the newest Eurozone members will only have minted these coins though (plus the 1c, 2c and 5c which haven't changed in common design). Also there are commemmorative E2 coins - e.g. Treaty of Rome coins of similar but individual design by each state, and then national

  • by Anonymous Coward

    If you compare a counterfeit-coin-detecting expert with a purpose-built handheld device, the answer is pretty obvious.

    Until the day the people who print counterfeit coins buy a purpose-built handheld device, of course, and there's no expert around to reprogram the device because he jumped off a bridge after losing his job.

  • counterfeit coins? i am not a counterfeiter but if i was going to counterfeit any form of currency i would do 20s 50s & 100s US dollar bills, a lot of work goes in to making them so i figure if i was to go in to that sort of criminal activity it would be the denominations that brought the best return
    • by DarkOx ( 621550 )

      That is why you would get busted. The most frequently counter fitted bills are the smaller denominations ones, fives, and tens. The reason people don't subject them to nearly the scrutiny. All and all there is not that much counterfeiting going on, and chances are if you accept a small bill there is very little change tendered so you are only out the inventory. If you accept a large bill like a 50 or a 100 you stand to loose quite a bit; you probably give not only your inventory but tender real currency

      • That is why you would get busted. The most frequently counter fitted bills are the smaller denominations ones, fives, and tens. The reason people don't subject them to nearly the scrutiny. All and all there is not that much counterfeiting going on, and chances are if you accept a small bill there is very little change tendered so you are only out the inventory. If you accept a large bill like a 50 or a 100 you stand to loose quite a bit; you probably give not only your inventory but tender real currency as change; so even though those are fakes less often they get looked at more.

        Actually, the most counterfeited bill is the $20; probably because it is the highest denomination in common circulation. The $100 is the next.

    • 100s? Why not go all the way? [bbc.co.uk]
  • How (Score:3, Insightful)

    by SEWilco ( 27983 ) on Tuesday November 17, 2009 @12:13AM (#30126016) Journal
    There are several methods.
    1. Smash coin with mouse. If coin bends, it is fake.
    2. Put mouse on balance scale. See how many coins are required to balance the scale. If the number of coins is different from the number of genuine coins required, at least one fake has been detected.
    3. Use the coin to pry the mouse apart. Look for scratches exposing a different color on the coin.
    4. Put the coin on the mouse. Burn the mouse. See if the coin melts.
    5. Put the coin on the mouse. Pour on the coin an acid which does not affect a genuine coin. Check if the coin survived.
    6. Line up coins the length of the mouse. See if the number of coins matches the number of genuine coins.
    7. Use coins to buy a mouse. See if the cashier rejects any coins.
    8. Use coins to pay for a call to the Secret Service. Report that someone might have used a counterfeit coin to pay for a phone call from this phone booth. Leave the mouse in the phone booth. Repeat until the "mouse counterfeiter" or the "mouse crank caller" is caught.
  • Sure would be nice to see this for US paper currency. Many cash registers are PC based at the motherboard level, and could support an optical mouse just fine. What a great bit of Open Source software it would be to create and release a program people could run in business, etc.

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