DE102006056567B4 - Method for authenticating a document - Google Patents

Abstract

Method for authenticating a document (1), characterized in that it comprises the following steps: a) application of a first RFID tag (2) to the document (1) which emits a first security information in the case of a radio query, b) subsequent printing at least a further RFID tag (3) which emits a second security information in the same radio query, wherein c) the RFID tags (2, 3) transmit the security information one after the other with a defined time delay, d) sending a radio query for the document ( 1), e) receiving time-shifted signals of the RFID tags (2, 3) by a reader as a common sum telegram, f) authenticating the document (1) on the basis of the sum telegram.

Description

To prevent counterfeiting of items, in particular documents (eg tokens, tickets, delivery notes, certificates, certificates, etc.), there are various methods. One of these methods involves authenticating objects by printing with one or two-dimensional optically readable encodings that may be encrypted and, for example, certification of the issuer, an integrity check, e.g. B. by means of so-called. Digests, and may include further information.

For the detection of objects are still automated readable radio brands, so-called RFID brands or RFID tags, known in which so far a kind of trustworthiness is assumed because RFID brands were not yet widely available or easy to manufacture. The problem is the increasing availability of polymer-based RFID tags that can be printed by inkjet printers. This increases the risk of counterfeiting RFID tags. Nevertheless, if counterfeit security is to be ensured in the conventional methods, then each RFID brand could be certified, which is very complicated and expensive, since this is a registration of at least part of the information emitted by the RFID tag at a trusted location, eg. As a trust provider, and requires a data exchange with this.

From the US 2004/0268132 A1 is a system for registering a user in a network, for example, in a public cafe with the help of RFID tags to remove. In one embodiment, two RFID tags are attached in the area of a service counter, on the one hand an access address and on the other hand a key for access to the network are provided. One of the RFID tags is shielded with the help of a manually operable by the operator screen, so that the information of the second RFID brand can be made available only for special customers.

In the US 2005/0134449 A1 is an RFID-based system for purchase actions to avoid, for example, thefts described. Here, a first RFID tag for product identification and a second RFID tag for identifying a buyer is provided. During the checkout process in the cashier area, an owner information in the product brand is changed to the buyer. In a second read-out area at the exit of the store, it is then checked again whether the owner information in the product mark agrees with the information on the buyer's mark.

From the US 2005/0001719 A1 Furthermore, it can be seen an RFID-based assignment system, in which two objects are each provided with an RFID tag, the two RFID brands indicate a membership to each other, for example, the affiliation of a key to the assigned car or the assignment of a ticket to verify a seat assigned to it.

The EP 0 427 342 A1 Finally, it deals with the problem of capturing signals from multiple RFID tags through a common reader. In order to avoid disturbances in the evaluation in a simultaneous reading, a time-delayed response of the various RFID tags is provided on a common request of the reader.

From the DE 10 2004 056 541 A1 discloses a method and apparatus for detecting a value-added indicia on a package, wherein the blasting of the coupon is at a radio frequency to energize the indicia and allow receiving information from the irradiated indicia, the information comprising an identifier and an identifier include value associated with the package.

From the DE 103 93 028 T5 For example, a slot machine is known which, for a loyalty program session, comprises, in particular, a body-contact-free data interface which is designed to read loyalty program instrument data without body contact and to initiate the loyalty program session body-contact-free.

It is an object of the present invention to provide a comparatively simple way of preventing or at least hindering counterfeiting of objects, in particular documents, by means of the RFID technology.

This object is achieved by a method according to claim 1. Advantageous embodiments are in particular the dependent claims.

For this purpose, the object is equipped with a first RFID tag, which emits a first information on radio query, and provided and set up that at least one further RFID tag is attached to it, which emits a second information in the same radio query, the RFID tags send the information one after the other.

The article may include, for example, a ticket, an electronic tokens, an attestation, a certificate, an article of non-conductive material, or a conductive material having a shield (e.g., paper, cardboard, plastic, etc.) or without metal coating). For example, the information sent by the first RFID tag upon radio polling may include an encryption key, e.g. A key of a symmetric or asymmetric key pair. The first RFID tag can also already independently state security information such as a genuineness or origin in the manner of an electronic stamp or watermark.

By way of example, the object can be provided and set up to accommodate at least one further RFID tag such that a suitable position for applying a further RFID tag is present, marked and / or prepared on it. A suitable position for a further RFID tag can, for. B. by an RFID reader or by optical detection of existing RFID tags done. It is also possible to find a suitable position for applying one or more further RFID tags by means of electrical or magnetic sensors. This ensures that two or more RFID tags are not attached to the same position.

The time-delayed signal transmission ensures that the signals do not overlap and can be read with sufficient resolution. This time offset can be set, for example application or customer related in the RFID chips, z. B. via an assignment of a transmission delay to one of the RFID tags, z. B. by means of a suitably designed protocol.

It is advantageous if at least one of the further RFID tags is attached to the object. In this case, the RFID tags can be positioned anywhere relative to one another. Thus, the RFID tags may be mounted on the same or on different outer surfaces of the article. If the RFID tags are located close together, it may be necessary to take steps to prevent the RFID tags from interfering with each other, such as: B. different antenna geometry (frequency bands), isolation of the antennas to each other, etc.

For interference-free query, it is advantageous if the RFID tags are mounted so far apart that they do not affect each other. Although due to the size of the article, the RFID tags can not be mounted sufficiently far from each other to provide a completely trouble-free operation, they are at least as far apart as possible so that they are minimally affected even without further measures as described above , If the signals of the RFID tags nevertheless influence, it must be ensured that they are clearly interpretable or correctable (eg by a suitable Haming distance with an applied coding).

It is advantageous for quick and inexpensive application if at least one of the RFID tags is printed on the article, preferably by polymer semiconductor material. In an alternative embodiment, the RFID tag is preferably adhered by means of a sticker.

It is advantageous if a summation telegram which contains the information transmitted in succession by the RFID tags in each case represents at least one authentication code. The successively transmitted information can therefore also be regarded as subkeys that are composed only when jointly queried to a correct key.

The invention is also achieved by a reading device which at least partially checks for authenticity a received signal which contains information received in succession.

In the following schematic embodiment, the invention is illustrated in more detail. The same features are described by the same reference numerals.

1 diagrammatically shows in diagrammatic form a document with a first RFID tag and a second RFID tag;

2 shows in sketchy side view the document 1 with applied second RFID tag.

1 shows a document 1 , z. B. a ticket on which an RFID tag 2 is printed. The document 1 However, z. For example, it may be a certificate, certificate, passport or other form of identity card, a document relating to persons, matters or rights, etc. The RFID brand 2 is programmed with an encryption key of a person involved in the output process (eg a concert organizer). For radio polling of the RFID brand 2 sends this information in the form of a response signal, which initially confirms only the authenticity and the origin of the paper. The imprint can change the RFID brand 2 very inexpensively applied to the document.

As indicated by the arrow, the document is the token, z. B a valid ticket, if another party, eg. B a customer who wants to use the service and wants to print out his ticket, another RFID brand 3 on the document 1 applies, for. B. by printing, sticking, etc. The other RFID brand 3 has programmed additional security information as well as additional data.

Here is the other RFID brand 3 to work with the first RFID brand 2 designed to be a first RFID tag 2 has defined time delay, so that when jointly polling the two RFID brands 2 . 3 they do not output time-overlapping signals.

When requesting the document 1 or RFID tags 2 . 3 By means of a request radio signal from an RFID reader (not shown), both RFID tags are activated and emit their response signals with a time delay. The reader receives the signals as a common collective telegram. The group telegram in turn is used for authentication, z. B. at the entrance of a concert hall.

Thus the authorization is carried out easily and securely.

2 shows the document 1 with the RFID brands 2 . 3 as a cross section in side view. The RFID brands 2 . 3 or their coupling coils are to improve the signal resolution only through the document 1 separated from each other. An improvement of the signal resolution is achieved in particular when it comes to document 1 is a non-conductive material (eg paper, cardboard, cardboard etc.).

Of course, the present invention is not limited to the embodiment shown. Thus, the first RFID tag may also be glued, z. B. by means of a sticker. The RFID tags can z. B. as a special printing paper, cardboard, stickers, tear marks, etc. are present. Alternatively, an origin confirmation may be issued by the second RFID tag; for example, to certify the authenticity of certificates, if instead of the usual paper now an RFID-labeled paper is used and the issuer applies his security information by means of the second RFID tag. Also, more than two RFID tags can be used. The RFID tags may be attached side by side or one above the other on the same surface or on different surfaces in any form (eg, glued, printed, pressed, etc.).

LIST OF REFERENCE NUMBERS

1

document

2

first RFID brand

3

another RFID brand

Claims (2)

Method for authenticating a document ( 1 ), characterized in that it comprises the following steps: a) application of a first RFID tag ( 2 ) on the document ( 1 ), which transmits a first security information in the case of a radio query, b) the following printing of at least one further RFID tag ( 3 ), which sends out a second piece of security information for the same radio poll, where c) the RFID tags ( 2 . 3 ) transmit the security information one after the other with a defined time delay, d) sending a radio query for the document ( 1 ), e) receiving time-shifted signals of the RFID tags ( 2 . 3 ) by a reader as a common sum telegram, f) authenticating the document ( 1 ) based on the sum telegram. Method according to claim 1, characterized in that the first RFID tag ( 2 ) is applied by a first party who transmits a first security information with a key code of the first party upon radio inquiry, and that the at least one further RFID tag ( 3 ) is printed by a second party.

Images