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3D Holograms Detect Fake Signatures
Roland Piquepaille writes "Several sources reported last week that a new technique that produces 3D holograms of handwriting could be used to detect fake signatures on checks, credit card receipts or other important handwritten documents. Here are pointers to Nature, Scientific American or BBC News Online. Instead of using 2D techniques to look at the sequence of pen strokes in a signature, this new method is based on 3D micro-profilometry which permits to translate the writing into an image showing dips and furrows of the sample so that anomalies can be detected. If you plan to imitate your spouse's signature, beware! Forensics have a new and very efficient tool. As an example, for the use of ballpoint pens on normal paper, the success rate was 100%. You'll find more details, references and pictures in this overview."
Abstract
For legal purposes there is a requirement for the validation of signatures and handwritten documents. A helpful method in this respect is the so-called superposed strokes analysis, based on the observation of some characteristics in the writing, such as some letters and their dynamics.
This paper introduces a promising new technique for superposed strokes analysis based on conoscopic holography. Through a non-contact 3D measure a 3D profile is created of the superposed strokes that allows the writing dynamics to be determined, such as, for example, if a stroke was drawn clockwise or counterclockwise.
We propose a 3D analysis by an opto-electronic system, in order to improve the graphology analysis for off-line signature verification.
okay, send me some samples of your signature and a blank check. And we'll see....
Some drink at the fountain of knowledge. Others just gargle.
What about the electronic signature pads in use at many stores, well, everywhere? I used to work at a 7-11, and I can tell you firsthand that the resolution *SUCKS* on these things. Nevermind that they don't take pressure readings. When we first got them my manager signed it with her real name, then "Micky Mouse". I couldn't tell the difference. It'd still be useful for things traditionally signed on paper (insurance policies, etc..), but as far as debit and credit transactions the majority (and a growing number of) of transactions will be unverifiable by this method.
E pluribus unum
Why does /. keep posting articles submitted by this guy? He has a shabby blog on radio.weblogs.com and does a poor job stealing other writers work; the site is a blatant commercial effort. Yet /. keeps putting Roland's stuff up and linking to it.
What's the deal? Is there some kind of commercial payola a la 1970's radio? Maybe the editor has a thing going with Roland, in a Clinton-McGreevy-esque way.
*Cringe* I didn't need any of those mental images.
I sign my wife's name all the time, and she sometimes signs mine. All perfectly legal, as long as neither one disputes it.
Simply claim you have power of attorney from your spouse. If, when asked, your spouse says "yes, I gave my permission", you're clear.
Of course, you better be DAMN SURE your spouse is going to back you up.
"yes, he did. Same way he gave me permission to sign his name on the check buying the mink coat..."
Learning HOW to think is more important than learning WHAT to think.
whilst your actual stroke path may be different for every signature, the order of your strokes and the pressure at different points means the paper is imprinted in a certain order.
;)
For instance, as I draw a capital B, i do my downstroke first, then sweep back up, to the left slightly, and then around for the 3 portion from top to bottom.
Even if somebody had my signature as an example, they would not be able to match my drawing style.
it would take a video of me performing the signature as well as paper samples, making it much much more difficult to achieve, and easier to detect.
This is one of the key elements of a signature that to this point has not been able to be utilised.
I love being left handed - it is my security by obscurity
liqbase
a video of me performing the signature as well as paper samples
I remember watching some signature-detection algorithm on BBC (program was QED actually) a while back which involved a fine grid on which you sign with a touch-pen. The hardware was pretty standard, like the pad which the UPS delivery guy carries around. The algorithm recorded which pixel was toggled (pressed) at what time; it compared this time-delay information to a known good signature time sequence, adjusting for spatial and temporal offsets. And then of course it also did a standard pattern-match between the final signatures. The advantage was that it could easily detect your normal signature from a slowly forged one, even if the end results looked identical. As I recall, it did not give *any* false positives at all under the test runs, but it did reject your own signature a little too often for it to be used widely.
Time flies like an arrow. Fruit flies like a banana.
The system is ancient but wide open to abuse. Several years ago a woman returned from holidays to discover that she had been married to her workmate. He had simply obtained all the paperwork, stamped it with his own seal and then having taken hers from her drawer, stamped it with her seal as well. The marriage was anulled, but the point is the personal seal is a little dangerous in my opinion.
Anyway, as a result, very few people I know in Japan has what I would call a signature, that is something that you write almost the same way each time. My own signature varies each time I write it an in fact has shrunk over the years, but always contains elements that appear to be hard wired into my hand and brain now. Even if I use a different grip, or even the wrong hand, the pattern is similar (thought obviously different). When my students try to sign something, they usually very neatly write their name in English.