the electric-discharge identification of banknotes

ISSN 1068�3755, Surface Engineering and Applied Electrochemistry, 2010, Vol. 46, No. 3, pp. 201–205. © Allerton Press, Inc., 2010.Original Russian Text © V.D. Shkilev, V.G. Nedioglo, A.N. Adamchuk, 2010, published in Elektronnaya Obrabotka Materialov, 2010, No. 3, pp. 4–8.

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The presented work consists of two parts, the firstpart advances the idea of the high level of banknoteprotection, and the second one expounds the techno�logical aspects of the realization of the method.

PART 1

The idea of a processes not completely controllableeven theoretically being used for the high�level protec�tion of documents is not new. As far back as the 1960s,S. Wiesner suggested using photons with assignedpolarized states [1]. This idea has not been realizabletechnologically up to now; nevertheless, the sugges�tion of S. Wiesner was actually brilliant, because newapproaches to cryptography that give the hope tosooner or later work out simple and cheap technolo�gies for manufacturing paper banknotes with the high�est level of protection have been developed with timeon its basis.

Now, let us discuss not the technology for the pro�tection of paper banknotes but a physical experimentcarried out in 1989 that helped electron interferencebe proved [2]. In this experiment, the researchers ofthe Laboratory for Advanced Research of the HitachiCompany, which was headed by A. Tonomura, andGakushuin University in Tokyo let an electron flowpass through a penetrable barrier equivalent to ascreen between two slots. After passing through thebarrier, each electron hit a fluorescent screen, thusproducing a short light flash. When observing eachflash, the Japanese experimenters could fix the placeof hitting of each electron. Modern position�sensitiveelectron counting systems were used in this expensiveexperiment. The obtained results proving the wavenature of matter are given in Fig. 1.

At first, (Fig. 1a—10 hits of the target by electrons;Fig. 1 b—100 hits), these flashes seem to be distrib�uted over the target�screen more or less regularly.

However, the hints at a definite picture begin toappear with time (Fig. 3 c—3000 hits). It arises that

the flashes prefer to appear in some places and avoidother places on the screen (Fig. 3 c).

In the fourth and fifth expositions (Fig. 1d andFig. 1e—20000 and 70 000 hits of the screen by elec�trons, respectively) obtained under the conditions of asignificant increase in “the exposure time,” the sensa�tions turn into an experimental fact—an alternatingseries of parallel bands proving that the electron inter�ference appears on the target.

Is this experiment the technology that enables thecreation of paper banknotes with the highest level ofprotection? No, this is only a physical experimenthinting at what direction should be taken in the devel�opment of the technology. The price of the above�described experiment is extremely high and multiplyexceeds the cost of manufacturing a banknote of themost frequently used nominal value. The technologyfor manufacturing a paper banknote with a high levelof protection must be several thousand times cheaperand account for a part of a banknote’s nominal value.

RESULTS AND DISCUSSION

Now, let us pass to the description of another phys�ical experiment [3] that actually opens the path to cre�ating the new technology.

The scheme of its performance is very simple.Small holes are punched in paper by the electric�dis�charge method. Then, these specimens are scanned inthe transmission mode by a usual scanner and storedin a database. The obtained pictures are processed by acomputer, and a number of parameters concerning thelocation of the spots are calculated.

Most of the experimental research in this field [4]describes the properties of the physical processes in aninterelectrode gap. The attention of the researcherswas almost not devoted to the information potential ofthese technologies [5].

The important factor permitting the places of theelectric punching in the paper to be easily scanned is

ELECTRICAL PRECISION TREATMENT OF MATERIALS

The Electric�Discharge Identification of BanknotesV. D. Shkilev, V. G. Nedioglo, and A. N. Adamchuk

Ministry of Information Development, ul. Pushkina 42, Kishinev, MD� 2012 Republic of Moldovae�mail: [email protected]

Received October 21, 2009; in final form, January 28, 2010

Abstract—New information technologies for manufacturing paper banknotes with a high level of protectionare presented. A method for forming a document database based on the association of wave and digital infor�mation is offered.

DOI: 10.3103/S1068375510030014

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SHKILEV et al.

that the black colored circle is marked by a laserprinter in the area that is to be punched. An individualnumeric code is also marked inside this circle presum�ably when creating a high�security document (Fig. 2).If an individual numeric code is absent, it is impossible

to build a database owing to the serious mathematicaldifficulties arising when using image recognition. Thedatabase is built on the combination of digital andwave (individual matrix) information. A document isfound in the database using a numeric code, and anindividual matrix is used to check whether a documentis counterfeit or not. A typical document containingan individual numeric code and an individual pictureobtained using electric punching is shown in Fig. 2.

Figure 3 shows a typical individual picture (withouta numeric code), from which it follows not only thatthe picture as a whole is individual but also that eachof the spots is original.

This typical picture (Fig. 3) insignificantly differsfrom Fig. 1b. The distinction is that the experiment is

(a) (c)

(b)

(e)

(d)

Fig. 1. Experimental proof of the existence of matter waves.

Agreement protocol

246584265

Fig. 2. A high�security document protected using an indi�vidual numeric code using electric�discharge technology.

Fig. 3. A typical individual image obtained experimentallyusing the electric�discharge technology.


THE ELECTRIC�DISCHARGE IDENTIFICATION OF BANKNOTES 203

1

2

3 4

5

6

2

Fig. 4. 100 Leus—a banknote of the Republic of Moldova: the paper base with a watermark (1); the numeric code of the banknote (2);the information�protected area (3); the Cartesian system of coordinates (4); punches made by the electric�discharge method (5); thetransparent protection layer (6).

ultimately simple and technological, and the resultsare realized directly on a paper carrier and not on adisplay screen.

The probability of the repetition of a matrix in thecase of individual processing was theoretically esti�mated at 10–400. From the standpoint of the protectionlevel, this value is equal to infinity. The technologicalaspect of the problem shows that infinity and 10–400 areweakly distinguishable notions.

Does this technology require that new specializedequipment be developed? However strange it mayseem, it does not. If a serial high�voltage 20–25 kVtransformer and additional electrotechnical detailsavailable to all are present, the equipment for manu�facturing an identification mark is assembled in15 min. The expenses for developing and manufactur�ing such equipment are negligible in comparison withthe possible financial losses [6].

When paper banknotes are manufactured, the com�bination of punches made by the electric�dischargemethod with already known polygraphic methods ofprotection may be considered as an important sign. Forthis purpose, punches are placed near the numeric codeof a paper banknote or watermark (Fig. 4).

The signs of authenticity of banknotes are suffi�ciently large in number. These are latent iridescentbands, diving metalized threads that are seen in thebackside of a banknote in the form of brilliant rectan�gles forming a dotted line, protection fibers, relief

images, latent images, watermarks, and microtexts.Recently (the modifications of the 1997 pattern), theBank of Russia has been introducing a new identifica�tion sign—micropunches. However, we know that themicropunches on the 1000 and 5000�ruble banknotesof Russia are made purely mechanically with the helpof needles rather than by the electric�dischargemethod. The banknote’s nominal value is marked on a1000�ruble banknote of the Bank of Russia with thehelp of micropunches. It is impossible to do this by theelectric�discharge method. As usual, this is regarded tobe a technological disadvantage. However, such a “dis�advantage” turns into a technological advantage in thefield of identification. All the banknotes of Russia havethe same illustration depicting the banknote’s nominalvalue. This is an accidental original set of punchesusing the electric�discharge technology. Therefore,this technology may be spoken about in the open press.The technology is easily realizable, but it cannot berepeated twice. When a banknote of Russia is looked atagainst a light source, the designation of the nominalvalue formed by the microholes is seen on it (Fig. 5).In the event of using the electric�discharge process,this is an accidental set of punches. The check forauthenticity is made by comparing the set of randomlyscattered punches with the analogous set stored in thedatabase.

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PART 2

An approach for direct counting of pixels enteringinto a ring was used in [3, 6] when analyzing thesquares. This approach has a number of disadvantages.It enables one to count only the total square of spots byrings and to reveal the stochastic waves but does notmake it possible to calculate the quantity and coordi�nates of the separate spots, which abruptly narrows thepossibility of researching the stochasticity of the pro�cess. Therefore, it is appropriate to change to a pro�gram that allows the statistical characteristics of each

separate sport to be calculated. For this purpose, thefollowing sequence of steps is usually used. The firststep is to binarize an image by one of the known meth�ods (W. Niblack, N. Ots, J. Bernsen, et al [7]) with theview to obtaining an image with sharp limits of thespots (Fig. 6). When binarizing an image, the bright�ness of each pixel is compared with the threshold valueof the brightness. If the value of a pixel’s brightness ishigher than that of the threshold brightness, the corre�sponding pixel will be “white” in the binary image;otherwise, it will be “black.”

(a) (b)

(c) (d)

Fig. 5. Punches on a banknote of the Russian Federation with a nominal value of 1000 rubles. (a and b) the polygraphic protectionin the form of hexahedrons is seen. Electric�discharge punches (c and d). The size of the reference section is 200 microns (a andc) and 500 microns (b and d).

Fig. 6. An image before and after binarization.


THE ELECTRIC�DISCHARGE IDENTIFICATION OF BANKNOTES 205

The second step is to distinguish the separate spotsin an image using a recursive or iterative algorithm.The essence of the iterative method is to sequentiallyscan an image with classifying the white pixels accord�ing to the principle of coherence. These operationsresult in a matrix in which all the pixels of each spot aredesignated by some number that may also be consid�ered as the sequence number of the spot (Fig. 7).

The third step is to calculate the statistical charac�teristics of a separate square spot, the coordinates ofthe center, the dispersion, the bevel, and the excess.

The initial image and set of calculated characteristicscan be stored in the database to be used in the work ofthe protection system.

CONCLUSIONS

A principally new technology for the protection ofpaper banknotes and documents with a high level ofprotection has been suggested.

REFERENCES

1. Wiesner, S., Conjugate Coding, Sigact News, 1983,vol. 15, no. 1, pp. 78–88.

2. Tonomura, A., Endo, J., Mamsuda, T., Kawasaki, T.,and Exawa, H., Demonstration of Single�ElectronBuildup of an Interference Pattern, Am. J. Phys., 1989,vol. 57, pp. 117–120.

3. Shkilev, V.D., Adamchuk, A.N., and Nedioglo, V.G.,The Electric�Discharge Technology for Protection ofHighly�Important (High�Security) Documents, Elek�tron. Obrab. Mater., 2008, no. 2, pp. 4–10.

4. Reter, G., Electron Avalanche and Breakdown inGases, Moscow: Mir, 1968.

5. Shkilev, V.D. et al, Patent of the Republic of Moldova3389, MD�BOPI, 2007, no. 8, p. 51.

6. Shkilev, V.D. and Adamchuk, A.N., New InformationTechnologies during Manufacturing Paper Banknoteswith the Quantum Level of Protection, InternationalConference “Information and Communication Tech�nologies 2009 ICT Chisinau, Republic of Moldova,pp. 186–188.

7. Fedorov, A., Binarization of Black�and�White Images: theState and Prospects of Development http://iu5.bmstu.ru/~philippovicha/ITS/IST4b/ITS4/Fyodorov.htm.

Fig. 7. Distinguishing of separate spots.