The invention relates to a device to be fastened in connection with an object, for identifying said object.

Bar codes, holograms or RFID tags are currently used, among other things, for verifying the origin and/or authenticity of the quality of various products. The packaging material of the product, some material(s) or parts used in the product can also be made in such a way that the authenticity of the product can be verified by means of a characteristic of the material or product part, such as colour, surface quality or composition. A characteristic that can be identified visually has the advantage that it does not require special equipment for the identification. Thus, identifying a pirate product, for example at customs, can be arranged relatively easily in practice, because no technical equipment will be needed for the identification. In many cases, however, the visually identifiable feature can also be easily mimicked so that the imitation is not found fake on the basis of mere visual inspection.

Even though a separate bar code reader is needed for reading a bar code, the security obtained with a bar code is also relatively weak, because the bar code can be easily reproduced for example by means of a copying machine or a printer and a scanner. Normally, a bar code only contains data describing the quality of the product or a mere code number identification, or, for example, information about the time of manufacture of the product.

An RFID tag can be more easily be provided with individual information on the product in addition to the code number identification. Information can also be added afterwards, if the RFID tag is of the RW type, that is, the chip contained in it is reprogrammable. For the RFID tag, the reading is per- formed by an RFID reader that is connected to the RFID tag by means of an RF signal. To secure the safety of the RFID tag, the code produced by the chip must be encrypted. To find out the encrypted code, there are thus two principle ways: unauthorized use of an RFID reader intended for reading the tag, or fabricating it. The safety of the RFID tag can be improved by using tags of the read-only type. In this case, however, it is not possible to include individual or, for example, production lot specific data on the product afterwards. A hologram may also contain information on a product, but normally a hologram is only used for verifying the authenticity of the product, based on the difficulty to copy the hologram. The authenticity of the hologram can be veri- fied either by visual comparison or by an electronic reading device which produces an image of the hologram or reads data stored optically in the hologram. Reproducing a hologram is technically difficult because devices intended for producing a hologram are not so easily available and the hologram often contains several previously unknown variables, such as the loca- tion and size of an object imaged in the hologram at the stage when it is generated. Holograms have also been used in combination with other identification methods to improve their safety. For example, US 6,618,024 discloses an RFID tag with a hologram attached to its surface to improve the appearance of the tag and simultaneously to hinder its forging.

Various special methods are known for providing a security level that is higher than the security level made possible by the RFID tags and/or holograms. However, such methods often have the disadvantage that the identification requires special equipment relating to this technique and/or the products to be identified by it, which cannot be easily provided, whose operation requires laboratory conditions, or whose application requires such expertise that is often not available for e.g. customs or other product supervision authorities. It is an aim of the present invention to provide a novel device based on the combination of an RFID tag and an optical data storage medium for identifying and verifying the authenticity of various objects, such as various products, requiring authentication. In particular, it is an aim of the invention to introduce a device intended for demanding identification applications and based on an RFID tag and an optical data storage medium, to achieve a higher security level in verifying the origin of products than in methods of prior art based on RFID tags and visually or optically readable identification means, such as holograms or bar codes, but whose use is simpler and requires less expertise than the special methods of prior art which are applied for achieving an advanced security level. The device according to the invention is characterized in what will be presented in the characterizing part of claim 1.

Significant advantages are achieved with the device according to the inven- tion with respect to identifications of prior art based on an RFID tag and/or visually or optically readable identification means. The device according to the invention is more difficult to copy or forge than the identification solutions of prior art which are based on, for example, an RFID tag and/or holograms, because the device always comprises, in addition to the identification code, a certificate which must be read/measured like an identification code automatically by a reading device, but whose storage/reading is performed by a method different from the storage/reading of the identification code. Furthermore, in the device according to the invention, the reading of the identification code and the certificate are always performed automatically by a reading device, which makes the authentication of objects, in practice, easier and more reliable than the use of such known identifications based on at least two different identification methods that apply an identification code stored on e.g. an RFID tag or a bar code and, as its certificate, e.g. a hologram that is identified merely by a visual inspection. Furthermore, the secu- rity of the authentication of the device according to the invention can be increased with respect to the solutions of prior art by making the identification code and the certificate dependent on each other in various ways in such a solution, because their identification is done by machine reading in such a way that the identification code and the certificate are always obtained in a format that is directly processable by a data processing medium, that is, for example a computer. It is thus possible to use, in addition to examining the identification code and the certificate, for example the order of reading or the interval between reading the identification code and the certificate stored on an RFID tag and a hologram, for identifying forged devices similar to the devices according to the invention.

In the following, the invention will be described in more detail with reference to the appended drawings, in which Fig. 1 shows a side view of a product equipped with a device according to the invention for its authentication, Fig. 2 is a principle drawing of the device in the product of Fig. 1 seen in a slanted view from above, the device being detached from the product, and Fig. 3 is a principle drawing similar to Fig. 2, of another device according to the invention, the device being shown in a slanted view from above,

Fig. 4 is a principle drawing of a third device according to the invention, the device being shown in a slanted view from the side, the material layers of the device being partly open, and

Fig. 5 is a principle drawing of a fourth device according to the invention, the device being shown in a partially cut view from behind.

Figure 1 shows a product 1 , which in this case is a plug to be connected to an electrical receptacle, but it could also be any other object or product to be identified, such as a spare part of a larger product unit to be replaced at intervals, whose authenticity should be verified. As shown in Fig. 1 , a space 2 for a device 3 according to the invention has been formed in the frame of this part made of plastic. The device 3 has been fastened in this space for example by gluing or by snap-in fastening. Removing the device 3 will leave a void recess in this space, so that in such an application, the mere lacking of the device 3 from the recess or the lacking of a recess in this part of the device will clearly show that the product has been forged. In principle, the RFID tag 5 of the device 3 could also be cast directly inside the frame of the product 1. Thus, only a hologram 8 used as an optical data storage medium in the device would constitute a separate part to be fastened to the frame of the product 1.

As shown in Fig. 2, the device 3 attached to the product 1 shown in Fig. 1 comprises a frame 4 of plastic made by die casting or another similar method, with an RFID tag 5 cast inside the frame and a hologram 8 attached to the surface that comes outside the product. The RFID tag 5 is, for exam- pie, a passive RFID tag known as such, comprising an RFID chip 6 and an antenna 7 connected to the same. The hologram 8 of the device is a hologram formed on a plastic sheet or a similar plate or foil and glued onto the outer surface of the device. In the example, the hologram 8 includes a 2D bar code 9 containing e.g. a given identification number or another character code with several characters. This identification number or character code is used as a certificate for the identification code stored in the memory of the RFID chip 6 inside the device. Alternatively, the hologram may also be provided with another code than a bar code in one or more dimensions, or a figure code. Thus, the certificate may consist of, for example, a set of characters to be read from the hologram, such as numerals, letters or fully abstract symbol signs whose reading may be based on either a 2D or 3D reading technique.

When the device of Fig. 2 is used for identifying the product shown in Fig. 1 , the identification of the product 1 is done automatically (= without manual input of data or characters to the reading device) by a reading device intended for this device 3. The reading device may comprise a data processor of its own, or the reading device is connected by a suitable data transmission connection to a separate data processing device, such as a computer, for automatic processing of the identification data to be formed for identification. The reading device also comprises an RFID tag 5 reader oper- ating in a way known as such, to activate the RFID chip 6 contained in the device, as well as a bar code reader for reading the bar code included in the hologram 8. The bar code 9 included in the hologram 8 is thus read by the same reading device intended for reading the RFID tag 5, simultaneously with the reading of the RFID tag 5 (or, for example, within a given time inter- val with respect to the reading of the RFID tag 5). In this application, the identification number or other character code included in the bar code 9 of the hologram 8 is used as a certificate, by which the reading device verifies that the identification code stored in the memory of the RFID chip 6 has not been forged. If the hologram of the device inspected by the reading device does not contain a bar code or if the bar code is incorrect, the reading of the RFID tag does not take place and the reading device indicates that said product is not authentic. It should be noted that the device may also operate, for example, in such a way that the certificate must first be given to the RFID chip which will transfer the identification code to the reading device first after receiving the certificate from the reading device. The reading device may also be a separate, so-called offline reading device, or a so-called online reading device connected to external systems, such as the Internet. An offline reading device will performs the authentication independently, without connections to external systems. In this case, the reading device could be, for example, a device comprising an RFID reader and a camera. The camera is used for reading the certificate included in the hologram 8, and the RFID reader is used for reading the RFID tag 5. The memory of such a reading device comprises the necessary software, by which the reading device reads the identification code and the certificate and performs the actual identification. The offline reading device could thus be, for example, a mobile phone equipped with a camera and an RFID reader. An online reading device is connected to external systems, for example, via the Internet, to search for the information required for the authentication in addition to the identification code and the certificate. This information is used to verify that the certificate and the certificate belong together and thereby that the product is authentic.

In the application shown in Fig. 2, the certificate and the identification code may alternatively have also been arranged in such a way that the identifica- tion code is in the hologram and the certificate is a certification code in the memory of the chip of the RFID tag. Furthermore, a reading device intended for reading the device 3 of the type shown in Fig. 2, or the RFID tag 5, may be provided with measurement of the interval between reading the identification code and the certificate, as well as a security function, in which the reading device or the RFID tag 5 rejects the identification code, if the interval between reading the identification code and the certificate differs from the limits set by a predetermined time window.

Figure 3 shows another device 10 according to the invention, to be attached, for example, to a product 1 of the type shown in Fig. 1 or another desired object to be identified. Also in this case, the identification code is a code stored on a chip 12 in the RFID tag 11 , whose reading requires the presence of a hologram 14. The reading device used in the device shown in Fig. 2 comprises an RFID tag reader and a measuring device for measuring the resonance frequency of an antenna 13 in the tag. The measuring device examines the resonance frequency formed together by the antenna 13 and the hologram 14 affecting its resonance frequency. If the resonance fre- quency is (within predetermined error limits) the same as the predetermined value for the resonance frequency, the identification code read from the RFID tag 11 is considered certified and the product authenticated. If the hologram 14 has been forged, that is, if the effect of the hologram in the device on the resonance frequency of the antenna is not the same as that of an authentic hologram, the reading device indicates that the product is not authentic. For this reason, the authentic hologram 14 is made of an electro- conductive material. To further increase the reliability of the identification, the hologram 14 may further be provided with, for example, an auxiliary visual or optical certification element, such as a figure or a 2D bar code similar to the preceding application. In the case of a bar code, the reading device must comprise a bar code reader similar to the preceding application, in addition to the device for measuring the resonance frequency. Figure 4 shows a third device according to the invention, which is an adhesive label 15 to be attached to an object to be identified. Here, the surface 16 of the adhesive label that remains visible (the upper surface) is provided with a hologram 17 used as a certificate for the adhesive label 15. The RFID tag has been fitted in the adhesive label 15 in the form of a so-called RFID inlay 18 in such a way that the adhesive label 15 comprises a surface layer 19 and an attachment layer 20, between which the RFID inlay 18 has been placed at the stage of attaching these layers. In Fig. 4, the surface layer 19 and the attachment layer 20 are shown partly opened and separated from each other. In this case, the hologram 17 has been formed in the surface layer 19 made of plastic. The RFID inlay 18 is, for example, an RFID transponder structure known as such, also called an RFID insert. Such an RFID transponder typically comprises, for example, a substrate of plastic film, to which the RFID chip and the antenna have been attached at the stage of manufacture of the inlay. An auxiliary layer of e.g. plastic or paper may have been laminated on top of the substrate, to protect the RFID chip and the antenna connected to it. The hologram 17 formed on the outer surface 16 of the surface layer 19 includes a bar code 21 , wherein it can also be read by machine. The attachment layer 20 is e.g. a paper or plastic film whose both surfaces are provided with an adhesive layer. The attachment layer 20 is glued onto the lower surface of the surface layer 19 so that the RFID inlay 18 remains between the lower surface of the surface layer 19 and the facing surface of the attachment layer 20. In this way, an adhesive label 15 is formed, in which the remaining adhesive surface of the attachment layer 20 is used as a gluing surface, by which the adhesive label 15 can be glued onto a desired object. It is evident that the RFID adhesive label can be formed in a number of ways by providing an RFID transponder in connection with various adhesive structures, whereby a transponder is obtained which can be attached to an object and whose materials and appearance are suitable for the application in question.

The principle drawing of Fig. 5 shows a fourth device according to the inven- tion. The device shown here is a product information tag 22 to be hung from an object, such as a product or a product package, a label 23 fastened to the other side of the tag (the side opposite to the side shown in the figure) containing written information, such as markings on the type, category or material of the product, as well as the price of the product. This kind of a device can thus be used for example in a clothes shop, for indicating the price, size and material information of a piece of clothing and for certifying its authenticity. For authentication, such a device according to the invention is naturally also provided with an RFID tag 24 and a hologram 25 used as an identification and its certificate. Also in this case, the RFID tag may be, for example, an RFID inlay integrated in the frame material of the product information tag 22, for example by a way similar to any of the applications of the preceding figure. In this case, the hologram 25 is placed on the opposite side with respect to the label, but in another application like this, it may also be on the same side as the label. Such a product information tag may also be equipped with an anti-theft function to replace RF-EAS (Radio Frequency Electric Article Surveillance), that is, a function to indicate if the object and the product information tag attached to it are brought outside a predetermined area. This function can be removed from the product at a control site when the product is first identified and the identification is certi- fied, and the anti-theft function on the RFID tag 24 is then switched off by a tag reading device (by entering this information in the memory of the RFID tag). A product information tag 22 equipped with the anti-theft function should be well attached to the product in such a way that it cannot be removed from the product for bringing the product outside the area under control. Furthermore, it is possible to use control, in which, for example, a part affecting the function of the RFID tag 24 is added elsewhere in the product or product package, to cause an alarm if it is not sufficiently close to the actual product information tag 22 when the product is being brought outside the area under control.

In many respects, the device according to the invention can be implemented in a way different from the above-described example embodiment. The identification code included in the RFID tag may, for example, include a supplier specific identification series, and the hologram may include a bar code to be used for certifying the authenticity of this code. In some embodiments, the device may also include an active RFID tag that transmits an identification signal continually at regular intervals to a stationary reading device placed at a suitable distance. The antenna of the RFID tag and the hologram together form a loop antenna that is broken if the hologram is detached from the device. Thus, the transmission of the identification signal is cut off and the stationary reading device indicates that the hologram used as a certificate has been removed from the product and that there is a possible attempt of stealing or illegal copying/forging of the product.

In some embodiments of the device according to the invention, it is possible to verify the identification code included in the RFID tag by using not only an optical data storage medium, such as a hologram, but also an auxiliary identification formed by, for example, a magnetic stripe, a laser engraving, paint or colour visible under UV light. A promising method for forming the auxiliary identification could be a product identification method based on particles made of material layers of different colours, applying a code system pre- sented in US 6,455,157; the method based on this is marketed under the trade name Secutag® e.g. in the Internet. In this method, the particles having a size of about 5 to 45 μm are made of, for example, 4 to 10 material layers of different colours which form a colour code that may contain several billions of different code alternatives. Normally, in such a method, two code groups are used. The first group contains in its code the same information for a plurality of products, and the second group contains in its code an information which is individual for each individual product. By such a method, an identification is obtained which is unique for each individual product and is very difficult to forge, because, in practice, an indefinite number of different codes can be formed. By such auxiliary identification methods, a multiple authentication can be set up with the RFID tag or a hologram in such a way that the lack of any single authentication method will reveal an attempt of forging the device. In this way, it is possible to achieve an even higher security level in the authentication of objects than in the above presented applications. It should further be noted that, for example, the above mentioned method based on particles of different colours or a code formed by laser engraving and/or by paint visible under UV light may, in some applications, also be used as the optical data storage medium to replace the hologram.

One way of providing an auxiliary certification for the identification is to combine positioning data to the identification. Thus, the certification will only function when the reading device also provides the RFID tag with positioning data which should meet the geographical position where the authentic object should be located. The positioning data can be retrieved by a GPS device in the reading device in the form of GPS position, base station data of a cellular network (rough position), or, for example, via the Internet.

As disclosed in the above description, the invention can be used to improve the certification of the identification in the object by means of a machine- readable auxiliary certificate connected to it. When this certificate is placed in a hologram, according to the invention, an additional advantage achieved is the fact that even without reading the certificate by machine, a customer inspecting the object visually will see the hologram which, as such, will give the customer an impression of an authentic and original product.

The invention is not limited to the above-presented example embodiments, but it may vary within the scope of the inventive idea presented in the appended claims.