EP1295262B2 - Method and apparatus for verifying the authenticity of documents - Google Patents

Description

The invention relates to a device for checking the authenticity of documents, in particular bank notes, documents of value or security documents, according to the preamble of the independent claims.

The authenticity of documents is generally checked by measuring certain authenticity features, for example optical, electrical or magnetic features, on a document to be checked and then checking the measured authenticity features on the basis of specified authenticity criteria. For example, the optical reflection behavior of the document is measured as an authenticity feature and then checked whether the measured reflection behavior falls below or exceeds a certain threshold value as an associated authenticity criterion. Depending on the test result, the document is classified as genuine or false.

An increase in the reliability in the detection of forgeries can be achieved, inter alia, by tightening the authenticity criteria when checking certain authenticity features, for example by raising or lowering threshold values. In practice, however, the authenticity criteria cannot be tightened arbitrarily, since otherwise the proportion of genuine documents not recognized as genuine - and possibly rejected or classified as false - would be too high.

In bank note processing machines, for example, which are used in particular in commercial banks for deposit checking and accounting, this would lead to increased expenditure in the manual and possibly further machine post-processing of bank notes that are not recognized as genuine.

In the case of the authenticity check in cash deposit machines, a general tightening of the authenticity criteria would mean that, in particular, used or soiled genuine banknotes, in which the expression of the authenticity features is reduced compared to freshly printed banknotes due to soiling or damage, are not recognized as genuine and consequently - depending on the application - be rejected or retained as an alleged forgery.

The reliability in the detection of counterfeit bank notes is therefore limited by the required low proportion of genuine bank notes not recognized as genuine. This is particularly problematic if, due to "soft" authenticity criteria, forgeries are not recognized as such and are put back into circulation, for example after a customer has deposited counterfeit banknotes at self-service recycling machines and then issues the banknotes not identified as counterfeit to other customers .

That from the DE 19618 541 A1 Known method relates to the determination of a sorting class from a number of banknote properties, such as denomination, security features and soiling. Here, measurement results for the bank note properties are first mapped onto discrete classes and combined to form a class vector. The class vector is finally compared with individual rule vectors which each correspond to a specific sorting class. If the class vector of the bank note matches a rule vector, the bank note is assigned the sorting class corresponding to the respective rule vector. With this method, sorting classes can be determined quickly and precisely. The derivation of a class for individual security features, ie the actual authenticity check, is carried out according to the methods known from the prior art, so that the problems described above also occur here: if, for example, by raising or lowering threshold values for authenticity features, the reliability is the authenticity check is to be increased or decreased.

From the EP 0 101 115 A1 a device for recognizing bank notes is known in which a digital image of the bank note is recorded and compared with a previously stored comparison image of a reference bank note. If a sufficiently reliable result is not obtained in a first comparison, in particular on one half of the bank note, the comparison can be repeated in other areas of the bank note, for example with other comparison values. This, however, opens up the possibility of specifically contaminating or damaging security-relevant areas of a counterfeit banknote to check other areas with possibly easier to imitate security features and thus - incorrectly - to bring about a positive check result

The object of the present invention is to provide methods and devices for authenticity checking with which documents can be checked with increased reliability, in particular without a simultaneous increase in the proportion of genuine documents incorrectly recognized as not being genuine.

This object is achieved by the features according to claim 1.

In the method for authenticity checking, at least two different authenticity classes are provided, each with one or more authenticity criteria, the individual authenticity classes differing from one another in at least one authenticity criterion. For the authenticity check, an authenticity class is selected from the different authenticity classes depending on the ascertained condition of a document to be checked and the document is checked using the authenticity criteria of the selected authenticity class, with clean and undamaged documents being checked with much stricter authenticity criteria than heavily soiled or damaged documents. The selected authenticity class is assigned to the document if its Authenticity criteria are met by the document. The authenticity criteria are, for example, threshold values or intervals for the authenticity features used for checking. For example, optical, magnetic, electrical or physical features can be used as authenticity features, for example optical reflection, transmission or emission, magnetic permeability, electrical conductivity, dielectric constant, thickness and format of the document and watermarks.

The invention is based on the idea of summarizing different authenticity criteria in the authenticity check of documents in several authenticity classes, the requirements for authenticity differing depending on the authenticity class, since each authenticity class has differently strict authenticity criteria. If, for example, an authenticity class with high requirements for authenticity is selected, e.g. with very high threshold values for optical reflection or transmission, the authenticity of documents that meet the authenticity criteria of this selected authenticity class can be affirmed with high probability. Documents which do not meet the authenticity criteria of a selected authenticity class can be checked using further selected authenticity classes with lower authenticity requirements, for example lower threshold values, whereby their authenticity can be affirmed with a correspondingly lower probability. Overall, the authenticity property, i.e. the measured authenticity features, of the documents to be checked is divided into different authenticity classes. This differentiation of the result of the authenticity check makes it possible to determine those documents which are more likely to be authentic than the authenticity check methods according to the prior art, whereby the reliability of the authenticity determination is increased overall. At the same time, the remaining documents can continue to be processed with the usual - i.a. "less strict" - authenticity criteria are checked, whereby the proportion of not recognized as authentic genuine documents remains low.

In a further development of the method it is provided that the denomination of the document is determined and then the authenticity class is selected as a function of the denomination of the document. The denomination is the value or currency of the document to be checked.

The condition of the document is generally given by characteristics such as degree of soiling, limpness, damage such as cracks, holes or missing parts in the printed image, as well as foreign bodies such as adhesive strips. The selection of the authenticity class for the authenticity check of a document is made depending, for example, on the degree of soiling of the document, with clean and undamaged documents being checked with significantly stricter authenticity criteria, e.g. higher threshold values, than heavily soiled or damaged documents. This significantly increases the reliability of the forgery detection of clean or slightly soiled documents. Overall, this state-dependent authenticity check enables documents in very good condition to be identified as genuine or false with a high degree of reliability. Since this only intensifies the checking of documents in very good condition, the proportion of genuine documents that are not recognized as genuine remains low.

Some of the authenticity criteria used for the authenticity check can be determined on the basis of forged documents. As a result, the authenticity check with defined authenticity criteria is expanded by an additional authenticity check with additional authenticity criteria, the additional authenticity criteria being determined on the basis of forged documents. The determination of the additional authenticity criteria generally takes place in a separate process, e.g. in specially provided facilities in which forged documents are examined, in particular for characteristic differences from genuine documents. From the differences found, additional authenticity criteria are determined, which are then fed to the authenticity checking method. Documents are still checked using fixed authenticity criteria and classified as genuine if the authenticity criteria are met. In addition, forgeries can be recognized if the checked documents do not meet the additional authenticity criteria determined on known forgeries, which preferably relate to characteristic differences between a found forgery and genuine documents. In this way, increased reliability is achieved in the detection of counterfeits, in particular with regard to known counterfeits that are in circulation.

Fig.1

den schematischen Aufbau einer Vorrichtung zur erfindungsgemäßen Echtheitsprüfung von Dokumenten;

Fig. 2

den schematischen Aufbau eines Systems zur Echtheitsprüfung anhand von an gefälschten Dokumenten ermittelten Echtheitskriterien und

Fig. 3

den schematischen Aufbau eines Systems zur Bearbeitung von einbezahlten Banknoten.

The invention will now be explained in more detail with reference to examples shown in figures. Show it

Fig.1

the schematic structure of a device for checking the authenticity of documents according to the invention;

Fig. 2

the schematic structure of a system for checking authenticity based on authenticity criteria determined on forged documents and

Fig. 3

the schematic structure of a system for processing deposited banknotes.

Figure 1 shows the schematic structure of a device for checking the authenticity of documents according to the invention. The documents 10, for example bank notes, provided in an input device 11 are withdrawn individually from the input device 11 and with the aid of a transport system 14 to the output device 12 promoted. There the documents 10 are sorted into three different sorting classes and output to corresponding output compartments 13. On the way between input device 11 and output device 12, a document 10 to be checked is transported past a measuring device 15. The measuring device 15 measures the authenticity features of the document 10 to be checked. State features characterizing the state of the document 10 are also measured. The dashed line in the measuring device 15 is intended to indicate that the measuring device 15 can have two or possibly more sub-devices in which authenticity and condition features can be measured separately. In principle, however, it is also possible to measure both authenticity and condition features together in one measuring device. In the example shown, the measuring device 15 is used to measure only one side of the document 10 to be checked. In general, however, the device can also be designed so that the document 10 can be measured from both sides, for example by two oppositely arranged measuring devices 15 through which the document 10 is transported.

Information about the features measured in the measuring device 15 is transmitted to an evaluation device 16 in which the authenticity check according to the invention takes place. The selection of a specific authenticity class and its assignment to the document 10 to be checked is preferably implemented by a computer program. In the computer program it is checked, for example, whether an authenticity feature measured on the document 10 to be checked, e.g. the optical reflection, is greater than a threshold value for the optical reflection belonging to the determined authenticity class. If the test result is positive, the specific authenticity class is assigned to the document 10, e.g. by writing a number characterizing the authenticity class in a variable characterizing the authenticity of the document 10. If the test result is negative, the computer program continues the test of the measured authenticity feature on the basis of lower threshold values belonging to other authenticity classes, i.e. less stringent authenticity criteria, and assigns a corresponding authenticity class to the document 10. Overall, this results in a division of the authenticity property, i.e. the measured authenticity features, of the documents 10 to be checked into different authenticity classes. If all of these tests give a negative test result, the document 10 is classified as false.

In the method according to the invention, the status of the document 10 is also determined, e.g. from the measured status features. The document 10 is then preferably assigned one of several status classes which are characteristic of the respective status of the document to be checked. When checking banknotes, three status classes are usually provided, namely for an unusable (unfit), usable (fit) or very good (ATM-fit) status. The selection of the authenticity class in the subsequent authenticity check then takes place as a function of the status class assigned to the document 10 to be checked. Here, banknotes in very good condition (ATM-fit) are subjected to very strict authenticity criteria, while banknotes in unusable or usable condition (unfit or fit) have to meet less strict authenticity criteria of other authenticity classes in order to be classified as genuine. To increase the reliability of the authenticity check, it is also possible here for an additional authenticity check to be carried out on documents 10 of a certain condition class, for example on banknotes in a usable (fit) or very good (ATM-fit) condition. Such an additional authenticity check can take place, for example, on the basis of already measured data on individual authenticity features.

The determination of the denomination can in principle also take place via the measuring device 15 and the evaluation device 16, but if necessary this can also be carried out in separate measuring and evaluation devices.

In a typical sorting mode, for example for use in a bank note processing machine for deposit checking and accounting, the documents 10 are divided into one or more sorting classes and output to corresponding output compartments 13. In this case, the output device 12 is controlled by the evaluation device 16 in such a way that banknotes - possibly of only one desired denomination - are output in a first of the output compartments 13, which have a very good (ATM-fit) condition and an authenticity class with high requirements the authenticity, ie strict authenticity criteria, has been assigned and which are in a desired position, ie a specific print pattern is visible from above and, if necessary, oriented in a specific way. Those banknotes to which no authenticity class could be assigned and / or which are not in a desired position and / or possibly do not belong to the desired denomination are output into a second output compartment, the so-called reject compartment. Banknotes that have been drawn in and / or transported incorrectly, for example double prints or folded banknotes, may also be output into this output compartment. Finally, all remaining banknotes are output in a third output compartment, ie usable (fit), unusable (unfit) and banknotes to which an authenticity class with lower authenticity requirements - ie less strict authenticity criteria - has been assigned. If, for example, a stack of banknotes of a certain denomination is entered in a mixed position, then with this sorting mode those banknotes of a certain denomination can be sorted out which are very likely to be genuine, in very good condition (ATM-fit) and at the same time in a desired location. Bank notes that meet these criteria can then be made available for immediate re-issue, for example in a self-service recycling machine.

Figure 2 shows the schematic structure of a system for checking authenticity on the basis of authenticity criteria which were determined on forged documents. The way such a system works differs from that in Figure 1 illustrated example mainly in that the authenticity check carried out in the evaluation device 16 takes place in two sub-steps. In a first sub-step, the authenticity check is carried out using authenticity criteria, which are preferably divided into authenticity classes. The selection of the authenticity class can here, as already in connection with Figure 1 has been explained, depending on the determined state of the document 10 to be checked. If the measured authenticity features meet the specified authenticity criteria, the document 10 is assigned the corresponding authenticity class. In a second sub-step of the authenticity check, there is an additional check using authenticity criteria that were determined on known forged documents. The determination of these authenticity criteria takes place in bank note checking machines suitable for this purpose, for example in a central bank or with a corresponding service provider. For reasons of data reduction, these are preferably authenticity criteria which are characteristic of the difference between a forged and a genuine document. The authenticity criteria used in the second substep of the authenticity check are transmitted in the example shown by a control device 31, e.g. from a server of a central bank or a central service provider, via a wired or wireless connection 32 to one or more test stations 30 at the same time. The corresponding data can, however, also be transmitted using suitable data carriers, for example by flash card, memory modules, floppy, CD or DVD. If a corresponding characteristic difference is now determined in the second sub-step of the authenticity check, the document 10 can be identified with a high degree of probability as a forgery, even if it meets the authenticity criteria in the first sub-step of the authenticity check. In principle, the chronological order of the two partial steps can be chosen as desired.

Overall, this system allows features and criteria for checking the authenticity of banknotes to be updated quickly and easily in any number of test stations 30 at the same time, so that a high level of reliability is ensured in the detection of counterfeit banknotes in circulation.

Figure 3 shows the schematic structure of a system for applying the authenticity check according to the invention. Documents 10, in this example bank notes, are paid into a commercial bank 39 by a depositor. The payment can be made at the terminal of a self-service recycling machine, for example. In the checking station 30, which can be part of the terminal, the bank notes are checked for authenticity. If the bank notes meet the very strict authenticity criteria of a selected authenticity class, they can be made available for immediate further output, for example at the same terminal, at other output terminals 34 and / or at a bank counter 36. All banknotes that do not meet these very strict authenticity criteria are fed to a central checking device 35, for example in a central bank 40, in order to be subjected to a further authenticity check, whereby so-called high security features are also used for checking, on the basis of which a particularly reliable detection counterfeit banknotes is guaranteed. Bank notes which meet these criteria can now be put back into circulation by being returned to a commercial bank 39 for disbursement at output terminals 34 or at a bank counter 36.

In this example, a control unit 31 is also provided, in which - as already in the description of Figure 2 indicated - on the basis of counterfeit banknotes, additional authenticity criteria are determined which relate to characteristic differences between genuine banknotes and banknotes recognized as counterfeit in the central checking device 35. The forgeries can be transmitted directly from the checking device 35 to the control unit 31. The authenticity criteria determined there are then transmitted via the connection 32 to the checking station 30 and can be used there for checking the authenticity of banknotes - possibly in addition to the authenticity criteria divided into different authenticity classes.

In order to enable tracing of deposited forgeries, characteristic data, e.g. print images and / or serial numbers, for the deposited banknotes can be stored together with data on the payer, e.g. account number and / or personal identification number (PIN), in the control device 31. If a banknote is recognized as a forgery in the central checking device 35, characteristic data, e.g. print images and / or serial numbers, of the banknote are transmitted to the control device 31. There, the person who pays the counterfeit banknote can be identified by comparing the stored and transmitted data. The control unit 31 can either be installed within the commercial bank 39, as shown, or it can be located outside the same, for example at a central service provider.

This in Figure 3 The system shown deals with the application of the method according to the invention in the authentication of bank notes on a deposit machine of a commercial bank. In principle, however, the authenticity check can also be carried out in a bank note processing machine in which bank notes - for example after paying in at the counter of a commercial bank - are entered by an employee for checking and / or sorting. The authenticity check and the subsequent process sequence for sorting, reissuing and / or forwarding for checking in a central bank are carried out analogously.

Claims (4)

1. An apparatus for checking the authenticity of documents, in particular bank notes, value documents or security documents, having

   - at least one measuring device (15) for measuring at least one authenticity feature on a document (10) to be checked, and

   - at least one evaluation device (16) for checking the measured authenticity feature using authenticity criteria,

   whereby the evaluation device (16) is configured for checking the authenticity of the document (10) using authenticity criteria of an authenticity class selected from several different authenticity classes, whereby the authenticity classes respectively comprise one or several authenticity criteria and mutually differ in at least one authenticity criterion, and whereby the requirements for authenticity vary in strictness depending on the authenticity class, characterized in that

   - the measuring device (15) is configured for measuring at least one condition feature which characterizes the condition of a document (10) to be checked, and the evaluation device (16) is configured for determining the condition of the document (10) from the measured condition feature and for selecting the authenticity class in dependence on the determined condition of the document (10), whereby clean and undamaged documents are checked with substantially stricter authenticity criteria than strongly soiled or damaged documents, and

   - the document (10) is assigned the selected authenticity class when the authenticity criteria thereof are fulfilled by the document (10).
2. The apparatus according to claim 1, characterized in that an output device (12) is provided for outputting documents (10) sorted according to their authenticity class and/or their condition and/or their denomination.
3. The apparatus according to either of claims 1 to 2, characterized in that the evaluation device (16) is configured for checking the authenticity of the document (10) using authenticity criteria that are ascertained using forged documents (10).
4. The apparatus according to claim 3, characterized in that there is provided a control device (31) which is configured for ascertaining the authenticity criteria using forged documents (10) and from which information about the authenticity criteria ascertained using forged documents (10) is transferable to the evaluation device (16).

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