WO2001071848A1

WO2001071848A1 - A tamper indicating radio frequency identification label

Info

Publication number: WO2001071848A1
Application number: PCT/US2001/008992
Authority: WO
Inventors: Peter Atherton
Original assignee: Mikoh Corporation
Priority date: 2000-03-21
Filing date: 2001-03-21
Publication date: 2001-09-27
Also published as: CA2387612C; WO2001071848B1; AU2001252935A1; CA2387612A1

Abstract

A tamper indicating label is provided. The label (100) may include RFID components and a tamper track (102) coupled to the RFID components. The tamper track (102) should be constructed from a destructible conducting path. Additionally, the tamper track (102) can be formed such that it is damaged when the label is tampered. In one embodiment, adhesion characteristics of the tamper track (102) are adapted to break apart the tamper track when the label is tampered, for example, by removal from an object. The RFID components may retain their RF capability and detect when the tamper track (102) has been damaged to indicate that the label has been tampered. Alternatively, the RFID capability of the RFID components may be disabled when the tamper track (102) is damaged, indicating tampering.

Description

Patent Specification for the Invention Entitled:

A TAMPER INDICATING RADIO FREQUENCY IDENTIFICATION LABEL

Inventor: Peter Samuel Atherton Address: 2903 Oakton Crest Place

Vienna, Virginia 22181 USA

Owner: MIKOH Corporation 2010 Corporate Ridge, Suite 700

McLean, Virginia 22102 USA

Background of the Invention

Radio Frequency Identification (RFID) is being used increasingly as a means to identify goods at a distance, without requiring physical contact or even line of sight access to the goods. RFID enables information about an item to be stored on an item, and in some implementations also allows this stored information to be modified at a distance. The most compact and cost effective means to provide this RFID capability is by means of a pressure sensitive (i.e. self adhesive) label incorporating an RFID capability.

The ability to detect remotely whether a pressure sensitive label or seal applied to an item has been tampered with or removed is becoming increasingly important in order to detect theft, product substitution, tampering, warranty violation and other problems.

A disadvantage of current pressure sensitive label technology is that it does not allow the remote determination of whether or not a label has been tampered with or removed and relocated.

Disclosure of the Invention

A tamper indicating label is provided. The label may comprise RFID components and a tamper track connected to the RFID components. The tamper track is preferably formed by destructible electronics. The tamper track may be modified when the label is tampered with. In one embodiment, the RFID components are able to detect the modification in the tamper track while maintaining their RFID capability. Detection of the modification in the tamper track indicates tampering with the label. In an alternative embodiment, the modification in the tamper track disables the RFID function.

In a further embodiment, the label comprises an RFID layer. The RFID layer may include a memory chip and at least one of an antenna or loop inductor. Means for attaching the RFID layer to an object may also be provided. The means for attaching may be an adhesive layer. The adhesive layer can support the RFID layer. A destructible conducting path may be sandwiched between the RFID layer and the adhesive layer. The destructible conducting path should be disrupted when the label is tampered. The disruption preferably modifies in some way the RFID characteristics of the RFID layer. In a further embodiment, at least a part of the destructible conducting path may in contact with the adhesive layer. The destructible conducting path can thereby be modified when the label is at least partially removed from a surface, and in turn, modify RFID characteristics of the label, indicating tampering. According to another embodiment, the invention includes an RFID system. A substrate having a top and a bottom surface is provided. RFID electronic components are applied to the bottom surface of the substrate. A conductive layer may also be formed in a pattern on the bottom surface of the substrate. An adhesive layer may support the substrate such that the RFID electronic components and the conductive layer are sandwiched between the substrate and the adhesive layer. The adhesive layer, the substrate, and conductive layer should have relative adhesion strengths such that when the system is partially removed from a surface to which it has been applied, at least one of the RFID components and the conductive layer is altered to modify the RFID characteristics of the system.

According to another embodiment of the invention, a security apparatus for indicating tampering is provided. Here, an object may be provided with a conducting path having at least two end points. A security label is arranged on the object. The security label may be a tamper indicating label as described above and should include RFID components and a destructible conducting path between the RF components and each individual end point.

In one of the more detailed embodiments of the invention, a security label is combined with an object. The security label may comprise RFID components and means for attaching the RFID components to the object. Destructible electronics may be connected to the RFID components. The destructible electronics can be broken when the label is at least partially removed from the object. The object comprises a surface for receiving the security label and a conducting path having two ends. The ends of the conducting path may be connected to the destructible electronics thereby forming a circuit through the RFID components, the destructible electronics and the conducting path. The RFID characteristics of the RFID components may be modified if the connection between the end points and the destructible electronics is broken.

According to another embodiment of the invention, a substrate having first and second portions is provided. The second portion of the substrate may be adapted to be looped back and connected to the first portion. An RFID transponder can be arranged on the substrate. A tamper track may be coupled to the RFID transponder and should extend at least partially into the second portion of the substrate. An adhesive layer should be provided on at least a part of the second portion of the substrate that includes the tampertrack. The tamper track in that part of the substrate may be adapted to be modified when the label is tampered with due to the relative adhesion strength of the tamper track. Brief Description of the Figures .

The present invention will now be described by way of non-limiting example with reference to the accompanying drawings, wherein: Figure 1 is a schematic illustration of the general design of a tamper indicating RFID label which is the subject of the present invention;

Figures 2a and 2b are a schematic illustration of a preferred embodiment and characteristics of the tamper indicating layer within a tamper indicating RFID label;

Figure 3 is a schematic illustration of a preferred embodiment of the tamper indicating conducting strip in the tamper indicating layer of a tamper indicating RFID label;

Figure 4 is a schematic illustration of a preferred embodiment of a tamper indicating RFID label in which the tamper indicating conducting strip is in series with an induction loop in said label;

Figure 5 is a schematic illustration of a preferred embodiment of a tamper indicating RFID label in which the tamper indicating conducting strip forms the induction loop of said label;

Figure 6 is a schematic illustration of a preferred embodiment of a tamper indicating RFID label in which the tamper indicating conducting strips form the antenna of said label;

Figure 7 is a schematic illustration of an variation of RFID label of Figure 6;

Figure 8 is a schematic illustration of a method ofmanufacturing an RFID label according to an embodiment of the invention;

Figure 9 is a schematic illustration of another embodiment of the invention;

Figure 10 is a schematic illustration of the top view, side view and bottom view of a preferred embodiment of a tamper indicating RFID label which is the subject of the present invention;

Figure 10a is a schematic illustration of the detail of a portion of the tamper indicating RFID label of Figure 1 ;

Figure 11 is a schematic illustration of a variation of the RFID label of Figure 10;

Figure 12 is a schematic illustration of loop tag based on the tamper indicating label design of figures 1 and 2;

Figure 13 is a schematic illustration of the use of a loop tag of the type illustrated in Figure 3; Figure 14 is a schematic illustration of an object having a RFID label applied.

Detail Description of the Invention

The term "passive", as used herein, refers to an RFID label or transponder which does not include an on-board power source such as a battery. The term "active", as used herein, refers to an RFID label or transponder which includes an on-board power source such as a battery. The advantages of an active RFID label, relative to a passive RFID label, is that an active RFID label can include continuous on-bόard functions such as a clock, and can usually enable longer read and write distances. A disadvantage of active RFID labels, relative to passive RFID labels, is that active RFID labels are physically larger due to the need to carry an on-board power source.

It should be appreciated that the terms label and tag may be used interchangeably in this document. Where the term label is used, the term tag may validly be substituted. The essential difference between the two is the thickness and types of material used in the construction. In general a label will be made from thin, flexible materials, while a tag will be made from thicker, stiffer materials. A tag may, for example, be similar to a plastic card with a pressure sensitive adhesive on the underside. Such tags may be used, for example, as compliance plates or rating plates or specification plates on various types of equipment. A tag, because of its greater thickness, is better suited to active RFID technology.

It should be appreciated that the illustrations herein are not to scale. In general the thickness of the label constructions (and component layers thereof) illustrated in the figures have been exaggerated, to illustrate more clearly the internal structures and components.

In general, a tamper indicating label is provided. The label may include RFID components and a tamper track coupled to the RFID components. The tamper track should be constructed from a destructible conducting path. Additionally, the tamper track can be formed such that it is damaged when the label is tampered. In one embodiment, adhesion characteristics of the tamper track are adapted to break apart the tamper track when the label is tampered, for example, by removal from an object. The RFID components may retain their RFID capability and detect when the tamper track has been damaged to indicate that the label has been tampered. Alternatively, the RFID capability of the RFID components may be disabled when the tamper track is damaged, indicating tampering.

Figure 1 is a schematic illustration of the general design of a tamper indicating RFID label according to an embodiment of the invention. Figure 1 shows schematically a pressure sensitive (i.e. self-adhesive) label 100 in cross sectional view. The label 100 may include four functionally distinct layers.

The RFID layer 101 may be a layer which includes RFID components, for example, an RFID memory chip. The label 100 may in some embodiments provide an "active" RFID capability, in which case the layer 101 can also include a battery or other power source. The second layer 102 may include one or more thin electrically conducting tracks which should be coupled to the RFID components in the layer 101. The tracks are known herein as "tamper tracks" since they provide a means to detect tampering with or removal of the label 100 from a surface to which it has been applied.

The layer 101 and the layer 102 may together provide an RFID capability. On the other hand, in some embodiments the layer 101 can provide an RFID capability in its own right, while the tamper tracks 102 can modify the RFID performance of the layer 101 depending on whether said tamper tracks 102 are damaged or not.

The RFID capability provided by the layer 101, or the layers 101 and 102 together, usually includes the ability to store information in the RFID memory chip in the layer 101 , and the ability to read and modify said stored information from a distance. Additional capabilities, such as the ability to encrypt stored information or control access to the stored information, may also be provided.

The third layer 103 may be an adhesive layer, which in some embodiments is a pressure sensitive adhesive.

The fourth layer 104 is a top-coat layer applied over the top of the RFID layer 101. The topcoat may be applied to protect the RFID layer and to provide a top surface to accept a printing process. The top coat layer 104 is not essential and in some embodiments may not be included. The finished construction is the adhesive label 100.

The tamper tracks 102 should be destructible. When the label 100 is applied to a surface and subsequently tampered or removed, the pressure sensitive adhesive 103 damages the tamper tracks 102 - for example, by tearing all or part of them from the underside of the layer

101 - which in turn affects the RFID performance of the label 100. Since the tamper tracks

102 are electrically connected to the RFID components in the label 100, and may form part of the RFID components of the label 100, the RFID function of the label 100 is modified if the label is applied to a surface and subsequently tampered or removed. In this way tampering with or removal of the label 100 can be detected at a distance via the change in the RFID characteristics and response of the label 100.

The terms "tampering" and "tampered" as used herein refer to complete or partial removal of a tamper indicating label, such as the label 100, from a surface to which it has been applied. In this document the term "destructible" is used in relation to the tamper tracks 102 in figure 1 and in relation to other tamper tracks throughout the document. In this context the term destructible means that the tamper tracks are designed to be damaged or broken in regions of the label which are tampered.

The tamper tracks 102 may be produced in one of a number of different ways. In one preferred embodiment, the tamper tracks may be produced by printing electrically conducting ink (such as a carbon/graphite based conductive ink or a precious metal ink). In another preferred embodiment the tamper tracks 102 may be produced using electrically conductive adhesive. In another embodiment the tamper tracks may be metallic tracks made of Aluminum, Copper or some other suitable metal.

In general the tamper tracks 102 should be made from a material, such as an electrically conducting ink, which has appropriate electrical properties but which does not have high intrinsic physical strength. In this way the tamper tracks 102 can be more easily disrupted or damaged as the label 100 is partially or completely removed from a surface to which it has been applied.

In some preferred embodiments the destructibility of the tamper tracks 102 may be enhanced by including a thin layer of a suitable adhesion modifying coating on the underside of the layer 101 either between the layer 101 and the tamper tracks 102, or between the tamper tracks 102 and the adhesive 103. At least a part of the tamper tracks should contact the adhesive 103. The layer of adhesion modifying coating may be applied as a uniform layer, or in a specified pattern, or in some other manner such that the properties of the adhesion modifying coating vary across the layer 101. In some embodiments multiple layers of adhesion modifying coating may be applied to "fine tune" the properties of the final composite adhesion modifying coating. .

Inclusion of a adhesion modifying coating between the RFID layer 101 and the tamper tracks 102 results in the adhesion of the layers to each other being greater or less in a particular region according to whether the adhesion modifying coating is present or absent in that region. Similarly, inclusion of an adhesion modifying coating between the tamper tracks 102 and the adhesive layer 103 results in the adhesion of the layers to each other being greater or less in a particular region according to whether the adhesion modifying coating is absent or present in that region. Usually, but not necessarily, the adhesion modifying coating reduces the adhesion of two layers which it separates, so that the two layers can be more easily separated. The relative adhesion between the layer 101 , adhesion modifying coating, tamper tracks 102 and adhesive layer 103 can be adjusted so that when the label 100 is applied to a surface and subsequently tampered or removed, the tamper tracks 102 are damaged in a pattern corresponding to the pattern of the adhesion modifying coating. In some embodiments the tamper tracks 102 may be physically separated in a pattern corresponding to the pattern of the adhesion modifying coating, with some of the tamper tracks 102 remaining on the layer

101 and the remainder of the tamper tracks 102 remaining on the adhesive layer 103. This damage to the tamper tracks 102 may affect the RFID performance of the label 100.

The adhesion modifying coating may be a layer of lacquer, or a layer of tamper indicating varnish (for example, similar to that used in some visual tamper indicating label constructions), or a layer of some other suitable material formulation.

The tampering indicating characteristics of one preferred embodiment of the label 100 are illustrated in figure 2, which shows the label 100 in cross section view before and after removal from a surface 201. Figure 2 illustrates in particular the physical disruption of the tamper tracks 102 during tampering or removal of the label 100. In figure 2(a) the label 100 is shown before removal from the surface 201. Here the tamper tracks 102 are intact and the label 100 exhibits its normal RFID operation. In figure 2(b) the label 100 has been partially removed from the surface 201. As the label 100 is removed, portions of the tamper tracks

102 remain with the top layer 101, and complementary portions of the tamper tracks 102 remain with the adhesive layer 103. The differential separation of the tamper tracks 102 may in some embodiments be enhanced or achieved through the inclusion of an adhesion modifying coating (as described above) in a specified pattern at the interface between the layer 101 and the tamper tracks 102, such that the tamper tracks 102 bond less strongly to the layer 101 where the adhesion modifying coating has been applied and therefore in such regions the tamper tracks 102 remain with the adhesive layer 103 when the label 100 is removed from the surface 201. As the label 100 is removed from the surface 201 , the tamper tracks 102 are damaged, and their electrical properties are thereby affected. This in turn affects the RFID properties of the label 100, since the tamper tracks 102 are electrically connected to the layer 101 which includes RFID components. In figure 2 the separation of (i.e. damage to) the tamper tracks 102 during tampering of the label 100 is shown to form a regular repeating pattern. It should be appreciated that the pattern of the separation may instead be irregular and may be on a larger or smaller scale relative to the size of the label 100 or the RFID components in the label 100 than shown in figure 2. The label 100 may also contain information in another format, such as a barcode, 2D barcode, or some other optical information storage format printed on the top surface of the top coat layer 104.

A preferred embodiment of the tamper tracks 102 will now be described with reference to figure 3, which shows an embodiment of the RFID label 100 in cross sectional view and looking from below through the adhesive layer 103 at the tamper tracks 102. In figure 3 the RFID layer 101 has two "through-connect" electrical connection points, 301 and 302, where the electrical circuitry in the RFID layer 101 is connected to the underside of the layer 101. In this embodiment the electrical connection between the points 301 and 302 by means of the tamper track 102 should be intact in order to maintain normal RFID operation of the label 100.

Preferably the tamper track 102 may be disrupted even if only a portion of the label 100 is tampered. In figure 3 the tamper track 102 runs around the perimeter of the underside of the layer 101 between points 301 and 302. This configuration for the tamper track 102 of figure 3 ensures that tampering of even a small portion of the label 100 will result in a break in the tamper track 102 and therefore a break in the electrical connection between the points 301 and 302, which in turn modifies the RFID behavior of the label 100.

It should be appreciated that other configurations of the tamper track 102 could also be employed. For example, in some embodiments the tamper track 102 may form all or part of an antenna, in which case the points 301 and 302 may not be electrically connected to each other via a single tamper track 102.

An RFID label will generally include an electronic memory chip connected to either an induction loop or an antenna. The induction loop or antenna may enable communication and data exchange with a remote reading device. (It should be appreciated that different types of antenna design may be employed.) Other electrical or electronic components may also be included in an RFID label. An active RFID label will include an on-board power source such as a battery.

Preferred embodiments of ways in which the tamper tracks 102 can be configured on the underside of the RFID layer 101 and coupled to the RFID layer 101 will be now be described by way of non-limiting example. It should be appreciated that in some embodiments the tamper tracks 102 may be designed to be destructible in some regions and durable in other regions. For example, the tamper tracks 102 may include some sections which are durable and rugged, joined by sections which are destructible.

The tamper tracks 102 may be connected in one of several different ways to the RFID layer 101 , depending on the design and operation of the RFID layer 101. Several non-limiting examples are listed below.

1. The tamper tracks 102 may be connected in series with an induction loop or antenna in the layer 101. 2. The tamper tracks 102 may constitute all or part of the induction loop or antenna of the label 100.

3. The tamper tracks 102 may be part of a tamper-sensing electrical circuit in the label 100 which is separate from the induction loop or antenna of the label 100.

Figures 4 to 7 are schematic illustrations of further preferred embodiments of the tamper indicating RFID label 100, showing both a cross sectional view and a view looking from below through the adhesive layer 103 at the tamper tracks 102.

Figure 4 is a schematic illustration of a preferred embodiment in which the tamper track 102 connects the points 301 and 302 and is in series with an induction loop 401 in the RFID layer 101. The RFID layer 101 may include the induction loop 401 and other components 402, which may be passive or active. For example, the components 402 in one embodiment may be a capacitor which, with the induction loop 401 , forms a resonant electrical circuit. Alternatively, the components 402 may include a passive electronic memory chip for storing data. The tamper track 102 should be intact for the RFID label 100 of figure 4 to be operational. When the label 100 is tampered, the tamper track 102 is broken and the RFID function of the label 100 can be disabled or modified. In this way it can be determined whether or not the label 100 has been tampered. An adhesion modifying coating may be included, as described above, to enhance destructibility of the tamper tracks 102.

Figure 5 is a schematic illustration of another preferred embodiment in which the tamper track 102 forms an induction loop 501 for the RFID label 100. In figure 5 the through-connect points 301 and 302 are connected to the RFID components 402 in the layer 101. In connecting the points 301 and 302, the tamper track 102 forms a number of loops, with the overall layout of the tamper track 102 acting as an induction loop. Tampering or removing the label 100 results in a break in the tamper track 102, thereby disabling or modifying the RFID function of the label 100. In this way it can be determined whether or not the label 100 has been tampered. An adhesion modifying coating may be included, as described above, to enhance destructibility of the tamper tracks 102.

Figure 6 is a schematic illustration of another preferred embodiment, which is a variation on the embodiment of figure 5. In figure 6 the tamper tracks 102 form an antenna, whereas in figure 5 the tamper track 102 forms an induction loop. The principal difference is that in figure 6 the points 301 and 302 are not connected together by a single tamper track 102. Instead there are two tamper tracks 102, one starting at point 301 and the other starting at the point 302. The two tamper tracks 102 form an antenna. In figure 6 a so-called meander antenna is illustrated, although it should be appreciated that other forms of antenna may also be employed. In some antenna designs the points 301 and 302 may be connected to each other by the tamper track 102. In figure 6 the through-connect points 301 and 302 are connected to the RFID components 402. Tampering the label 100 should result in damage to at least one of the tamper tracks 102, thereby affecting the characteristics of the antenna and modifying or disabling the RFID function of the label 100. In this way it can be determined whether or not the label 100 has been tampered. An adhesion modifying coating may be included, as described above, to enhance destructibility of the tamper tracks 102.

Figure 7 is a schematic illustration of another preferred embodiment, based on the embodiments of figures 5 and 6. The principal difference between the designs illustrated in figures 5 and 6, and the design illustrated in figure 7 is that in the design of figure 7 the RFID components 402 are on the underside of the layer 101. In some embodiments the RFID components 402 may comprise only an RFID memory chip, in which case in the design of figure 7, both the RFID memory chip 402 and the tamper tracks 102 are on the underside of the layer 101. The tamper tracks are designed to be destructible, as described herein. An advantage of the design of figure 7 compared with the designs of figures 5 and 6 is that in the design of figure 7 there is no need for through-connects to the bottom side of the layer 101 , since the RFID memory chip is on the bottom side of the layer 101. In the design of figure 7 the tamper tracks 102 may form an induction loop, as in the design of figure 5, or may form an antenna, as in the design of figure 6. In figure 7 an antenna is shown. An adhesion modifying coating may be included, as described above, to enhance destructibility of the tamper tracks 102.

In order to provide an additional indicator of tampering, the label 100 may be designed to show visual evidence of tampering if the label is removed from a surface to which it has been applied. Visual tamper indication can be achieved in several ways. In one embodiment a thin colored layer is applied to the underside of the RFID layer 101. A pattern of adhesion- modifying layer may be applied to the underside of the colored layer. The adhesion- modifying layer may be the same layer or a layer in addition to the adhesion modifying coating described above. The presence of the adhesion-modifying layer modifies the adhesion of the colored layer to the adhesive layer 103 such that when the label 100 is removed from a surface to which it has been applied, the colored layer breaks up. Areas of color may adhere to the adhesive layer 103 and other complementary areas of color may adhere to the RFID layer 101. An alternative to this embodiment is to apply a pattern of said adhesion modifying layer directly to the underside of the RFID layer 101 and apply said thin colored layer to the underside of said adhesion modifying layer. In another embodiment, the adhesion modifying coating may be applied directly to the underside of the RFID layer 101 and a colored adhesive can be used as the adhesive layer 103. In this case, when the label is removed from a surface to which it has been applied, the colored adhesive 103 should break up and areas of the colored adhesive may adhere to the RFID layer 101 and complementary areas of the colored adhesive 103 may adhere to the surface. It should be appreciated that other methods may be used to produce a visual tamper indicating effect.

When using a visual tamper indicating effect, a portion of the RFID layer 101 and top coat 104 (if a top coat 104 is present) should be transparent so the visual effect can be seen by looking through the RFID layer 101 and top coat 104. This enables easy inspection of the visual tamper indicating feature without having to remove the label. The RFID components in the RFID layer 101 , such as a memory chip, may not be transparent, but should only occupy a small portion of the surface area.

Additionally, it may be desired to print information or patterns on the label. For example, as described above, a bar code or serial number may be printed on the top surface of the RFID layer 101 or on the top surface of the top coat 104 (if a top coat 104 is present). Enough of the RFID layer 101 and top coat 104 should be transparent to allow the visual tamper indicating feature to be visible.

Method of Manufacture

A preferred method of manufacture for the label configuration described above in relation to figure 7 is now described and illustrated schematically in figure 8, which shows illustrations of an RFID label construction and method of manufacture in cross sectional view.

The diagram of figure 8 illustrates a passive RFID label construction, in which the RFID components 402 consists of an RFID electronic memory chip. A pattern 801 of adhesion modifying coating may be applied to the underside of a substrate layer 802, which may in one embodiment be a polyester layer. The tamper tracks 803 can be printed on the underside of the adhesion modifying coating. If necessary the tamper tracks can include a "cross-over", where a tamper track 803 crosses over itself along a bridging layer of electrical insulator. The tamper tracks 803 may be configured to form either an induction loop or antenna of appropriate design and characteristics. An RFID electronic memory chip 804 can then be mounted on the underside of the layer 802 and positioned to connect to appropriate terminating points on the tamper tracks 803. The RFID chip 804 and tamper tracks 803 should form an RFID transponder. The construction 805 consisting of substrate 802, adhesion modifying coating 801, tamper tracks 803 and RFID chip 804 is cut into individual transponders 806. Each transponder 806 is placed in a specified position on the underside of a top coat layer 807 and may be fixed in position with a thin adhesive layer. A layer of pressure sensitive adhesive 808 may be applied to the underside of the top coat 807 and individual transponders 806. The resulting construction consisting of top coat layer 807, individual transponders 806 and adhesive layer 808 is mounted on a suitable carrier film 809 and produced in roll form. The resulting roll is die cut into individual labels 810 mounted on the continuous carrier film 809, where each label 810 includes one transponder 806.

In a variation on the method of manufacture illustrated in figure 8, the tamper tracks 803 may be produced using an electrically conducting adhesive instead of an electrically conducting ink.

Tamper Indicating RFID Label with Tracking Capability

Figure 9 is a schematic illustration of another preferred embodiment in which the tamper track 102 forms part of a separate tamper indicating electrical circuit. As shown in figure 9 the RFID layer 101 may contain an induction loop or antenna 901 and other electronic components 402, including an electronic memory chip, to provide an RFID capability. The RFID layer 101 should be capable of interacting with an RFID reading device to allow reading of or modification to data stored in the electronic memory chip. The through-connect points 301 and 302 are connected to the components 402 in the layer 101 , and to each other via the tamper track 102. The components 402 should be configured to respond differently to a signal from an RFID reader depending on whether or not the points 301 and 302 are connected to each other via the tamper track 102 or not. If the tamper track 102 is intact, the label 100 will respond in a specified manner to an RFID reader. On the other hand, if the label 100 is tampered, so that the tamper track 102 is damaged and the points 301 and 302 are no longer connected to each other via the tamper track 102, the label 100 should still respond to an RFID reader but in a different manner, thereby indicating that the label 100 has been tampered. In this way the label 100 of figure 9 can provide an RFID means to (i) determine whether the label 100 is present, (ii) read data from the label 100 and modify data stored in the label 100, and (iii) determine whether the label 100 has been tampered. In one preferred embodiment the components 402 may consist only of a passive RFID electronic memory chip, and the tamper track 102 forms a connection, which may be separate from the induction loop or antenna 901, between two contact points on the memory chip.

In a variation on the embodiments described above, the components 402 may undergo an irreversible change if the label 100 is tampered and the tamper track 102 is damaged, so that even if the tamper track 102 is subsequently restored, the label 100 will still respond to an RFID reader with a signal indicating it has been tampered. In one preferred embodiment the RFID components 402 is "active" (i.e. powered) and is configured to test the integrity of the tamper track 102 either continuously or at specified intervals. In this embodiment if the RFID components 402 detect that the tamper track 102 has been disrupted they may then preferably be configured to record data to this effect in the electronic memory chip within the components 402, preferably in a manner which is permanent and irreversible. Preferably, if the components 402 are active, they may also include a clock. In this case, the date and time of any tampering of the tamper track 102 or label 100 may also preferably be recorded permanently and irreversibly in the electronic memory chip within the RFID components 402.

A preferred embodiment of the tamper indicating RFID label configuration of figure 9 will now be described by way of non-limiting example with reference to the schematic illustrations shown in figures 10 and 11.

It should be appreciated that the term antenna as used below may refer to a conventional antenna or to an induction loop (which is used as an antenna at some RFID operating frequencies).

Figure 10 is a schematic illustration of a tamper indicating RFID label 1000 shown in top view, cross sectional side view, and bottom view.

The label 1000 may include a substrate layer 1001 made of, for example, polyester or some other suitable material. On top of the substrate layer 1001 , electronics to form an RFID transponder, which provides an RFID function, may be applied. The electronics may include an RFID electronic memory chip 1002 and an antenna 1003. (In figure 10 an antenna 1003 in the form of an induction loop is shown.)

Figure 11 is a more detailed schematic illustration of an example of the electrical connections to the electronic chip 1002.

The chip 1002 and antenna 1003 should provide an RFID capability, which may include the ability to store information in the chip 1002, the ability to read information from the chip 1002 at a distance using a suitable RFID device, and the ability to modify information in the chip 1002 from a distance using a suitable RFID device.

The chip 1002 may include two contact points, or contact pads, connected to the antenna 1003, as illustrated in figure 10(a).

The two contact pads on the chip 1002 can be connected via electrical "through-connects" 1004 to the underside of the substrate layer 1001. One or both or neither of these two contact pads may be the same as the contact pads used to connect the chip 1002 to the antenna 1003. Figure 10(a) shows the through-connects 1004 directly beneath the chip

1002. It should be appreciated that other configurations may instead be used for the through-connects 1004. In another preferred embodiment, the through-connects 1004 are positioned away from the contact pads on the chip 1002, and electrical tracks on the top surface of the substrate layer 1001 connect the contact pads on the chip 1002 to the tops of the through-connects 1004.

The two through-connect points 1004 on the underside of the substrate layer 1001 are connected to each other by means of a tamper track 1005 which is positioned on the underside of the substrate layer 1001.

A layer of adhesive 1006 may also be applied to the underside of the substrate layer 1001 and tamper track 1005. Preferably said adhesive 1006 is a pressure sensitive adhesive.

A top layer 1007 may be applied over the top of the substrate 1001 , chip 1002 and antenna

1003. The top layer 1007 can provide protection for these components and can also provide a surface to accept printing - for example printing of a number, a barcode, a logo, or other image. It should be appreciated that in figure. 10 the top view is a view looking through the top layer 1007, the side view is a cross sectional side view, and the bottom view is a view looking though the adhesive layer 1006.

The tamper track 1005 is preferably applied to the underside of the substrate layer 1001 , along with one or more layers of adhesion modifying coating to enhance the destructibility of the tamper track 1005. Consequently, if the label 1000 is applied to a surface and subsequently removed, the tamper track 1005 should be broken or disrupted so as to interrupt the electrical connection between the through-connect points 1004 on the underside of the substrate layer 1001. Application of the tamper track 1005 and any other adhesion modifying coatings to the underside of the substrate 1001 to enhance the destructible nature of the tamper track 1005 may preferably be carried out as described in the following provisional patent applications, which are incorporated by reference:

1. "A Tamper Indicating Radio Frequency Identification Label and Methods for the Manufacture Thereof; Filed 28 July 2000; U.S. Provisional Patent Application No.:

60/221 ,640

2. "A Tamper Indicating Radio Frequency Identification Label and Methods for the Manufacture Thereof; Filed 28 September 2000; U.S. Provisional Patent Application No.: to be advised

The tamper track 1005 may be laid out in a number of different ways on the underside of the substrate layer 1001. In the preferred embodiment illustrated in figure 10, the tamper track runs from one through-connect point 1004 almost all the way around the perimeter of the underside of the substrate layer 1001 and then back to the other through-connect point, with the outward and return paths of the tamper track 1005 very close together in order to avoid any electrical induction effects which may interfere with the antenna 1003 positioned above on the upper surface of the substrate layer 1001. The width and thickness of the tamper track 1005 can be adjusted to provide the correct properties in terms of electrical resistance and physical destructibility. The path made by the tamper track 1005 may run inside, or outside, or directly beneath the antenna 1003, which in figure 10 is an induction loop. In one preferred embodiment the tamper track 1005 forms a path which is outside the outer perimeter of the induction loop 1003, thereby ensuring that any disturbance around the perimeter of the label 1000 will cause the tamper track 1005 to be disrupted.

When the label 1000 is applied to a surface, the tamper track 1005 is intact and the corresponding contact pads on the chip 1002 are electrically connected to each other. When the label 1000 is removed or substantially tampered with, the tamper track 1005 should be broken or disrupted and there will thςn be an open circuit between the corresponding contact pads on the chip 1002. When such an open circuit occurs, the function of the RFID chip 1002 or the information stored in the chip 1002 will be modified in a way which can be detected by an RFID reader.

If the label 1000 is passive (i.e. without an on-board battery or other power source), the modified chip function or information can be detected during the first read operation of the label after the label 1000 is removed or tampered, and the reader (if it has a write capability) can be programmed to write data back to the chip 1002 to indicate that the label 1000 has been removed or tampered. Said data which is written back to the chip 1002 to indicate removal or tampering of the label 1000 is preferably permanent and irreversible, to prevent the memory contents of the chip being altered back to the original state to disguise the fact that the label has been moved or tampered. There is therefore disclosed herein an RFID read/write device capable of detecting the change in RFID performance of the label 1000 when the label 1000 is tampered, and writing data back to the chip 1002 within the label 1000 to indicate such tampering has occurred, said data preferably being written into the chip 1002 so as to be permanent and irreversible.

If the label 1000 is active (i.e. has an on-board battery or other power source), it can be configured such that any disruption to the tamper track 1005 can be detected internally within the label 1000 without requiring an RFID read operation. When such disruption to the tamper track 1005 is detected internally, the chip 1002 can be programmed to modify its own memory contents to indicate that the label 1000 has been removed or tampered. Said modification to the memory contents of the chip 1002 to indicate removal or tampering of the label 1000 should preferably be permanent and irreversible, to prevent the memory contents of the chip being altered back to the original state to disguise the fact that the label has been moved or tampered.

Hence the label 1000 may function as a normal RFID label when it is first applied to a surface. After is the label is moved or tampered, the RFID function of the label 1000 may be maintained and information can be read from and written to the RFID chip 1002, while the label also provides an RFID means to determine that it has been moved or tampered.

Figure 11 is a variation on the preferred embodiment of figures 9 and 10. The basic design of the label 1000 in figure 11 is the similar to that of figure 10. The difference in the design of figure 11 is that the tamper track 1005 extends well beyond the antenna 1003 or other RFID components in at least one direction. The tamper track 1005 should run around the perimeter of the label 1000 and defect tampering of any edge portion of the label, whether near the chip 1002 and antenna 1003 or at the end of the label away from these components. The label 1000 can, for example, be applied around a corner so that the chip 1002 and antenna 1003 are on a flat surface while the other end of the transponder, which includes the tamper track 1005, extends around the corner.

Figure 12 is another variation on the embodiment of figures 10 and 11. Figure 12 is a schematic illustration of a tamper indicating RFID loop tag 1200, shown in top view, side view and bottom view.

In figure 12, the tamper track 1005 on the underside of the substrate 1001 extends beyond the antenna 1003 and forms a "tail" 1201. In the embodiment shown in figure 12, the tamper track 1005 is straight. The substrate 1001 may be cut approximately to the shape of the electronics, so that the loop tag 1200 is broad at the end which includes the antenna 1003 and narrow at the tail 1201. Alternatively, the loop tag may be cut into any other shape around the electronic components. Preferably, the tamper track 1005 will extend to the end of the tail 1201.

A bottom layer 1202 may also be applied to a specific portion of the underside of the substrate 1001 and tamper track 1005. The tamper track should extend into the region 1203 of the underside of the substrate 1001 which is not covered with the bottom layer 1202. In the region 1203 where the bottom layer 1202 is not applied, an adhesive, such as a pressure sensitive adhesive 1204 may be applied to the underside of the substrate 1001 and the tamper track 12100505.

A top layer 1007 may be applied over the top of the substrate 1001 , chip 1002 and antenna 1003. The top layer 1007 may provide protection for these components and may also provide a surface to accept printing - for example printing of a number, a barcode, a logo, or other image.

It should be appreciated that in figure 12 the top view is a view looking through the top layer 1007 to the chip 1002 and antenna 1003, and the bottom view is a view looking through the bottom layer 1202 and adhesive 1204 to the tamper track 1005 and through-connects 1004.

In operation, the loop tag 1200 may be bent into a loop 1205 and the region 1203 of pressure sensitive adhesive can be pressed against a region of the bottom layer 1202, as shown. The pressure sensitive adhesive 1204 should hold the loop 1205 closed. In another variation, a loop 1206 may be formed by pressing the region 1203 of pressure sensitive adhesive 1204 against a region of the top layer 1007, as also shown. (It should be noted that the illustrations of the loops 1205 and 1206 do not show the internal components - such as the chip 1002, antenna 1003 and tamper track 1005 - or the separate layers of the loop tag construction.) The two regions of the loop tag which are joined together in this way by the pressure sensitive adhesive 1204 preferably both include electronics - for example, the chip 1002, or the antenna 1003, or the tamper track 1005 - in order to ensure the closed loop cannot be cut and the loop opened without the RFID performance of the loop tag 1200 being affected. For example, the tamper track tail 1201 may be looped back and fixed to another portion of the tamper track tail 1201 or may be looped back and fixed to a region of the underside of the antenna 1003 (as illustrated in the loop 1205). The substrate 1001 , pressure sensitive adhesive 1204, tamper track 1005, and any adhesion modifying coatings which are applied (as described in relation to figures 9 and 10), are preferably designed as described herein such that the tamper track 1005 is damaged when the closed loop is pulled apart in the region of pressure sensitive adhesive 1204, thereby modifying the RFID performance of the loop tag 1200, as described above in relation to the label constructions of figures 9 and 10. A similar modification to the performance of the loop tag 1200 will occur if the closed loop 1205 or 1206 is cut in order to open the loop.

The loop tag configuration illustrated in figure 12 may be used to secure the tag 1200 around an item such as a handle, or to secure two items together. Figure 13 is a schematic illustration of the use of the loop tag 1200 to detect opening of a container 1300 which includes a body 1301 and lid 1302. The body 1301 and lid 1302 have holes 1303 which align when the lid 1302 is placed properly on the body 1301 of the container 1300. Figure 13 shows a cutaway cross sectional view of a portion of the body 1301 and lid 1302 of the container 1300 in the region of the holes 1303. In this embodiment the loop tag 1200 is applied to the container 1300 with the open loop portion 1304 passing through the aligned holes 1303. In this implementation the RFID chip 1002 in the loop tag 1200 may store information about the contents of the container 1300. If the loop tag 1200 is removed from the container 1300, either by pulling the loop apart to open the loop or by cutting the loop tag, the tamper track 1005 will be interrupted and the RFID performance of the loop tag 1200 will be modified in a manner detectable by an RFID reader, as described above in relation to the label construction of figures 9 and 10.

It should be appreciated that the loop tag 1200 does not need to have a narrow tail region. The loop tag may instead be rectangular in shape. It should be appreciated that variations on the preferred embodiment of figure 9 to 12 are possible. For instance, taking the design of figure 10 as an example, the chip 1002, antenna 1003 and tamper track 1005 may all be on the underside of the substrate 1001. In this case it may be necessary for the tamper track to cross over the antenna 1003, on a "bridge" layer of electrically insulating material, in order to extend outside the antenna. The advantage of this embodiment is that the through-connects 1004 described in relation to the designs of figures 9 and 10 are not required.

In another embodiment of the invention, a tamper indicating label is incorporated with an object to which the label is to be applied. The label used may be any of the embodiments described above. Figure 14 illustrates a label 1401 applied to an object 1402. A conductive path 1403 should be incorporated into the object. For example, a conducting path of electrically conducting ink may be formed around the object. The conducting path 1403 on the object 1402 should have at least two end points. The tamper tracks in the label 1401 should have a corresponding number of connection points. When the label 1401 is applied to the object 1402, each end point should be connected to a connection point. The conducting path on the object 1402 and the tamper tracks in the label 1401 should together form one or more circuits, each from a tamper track to an endpoint, through the conducting path on the object, to the other end point and back to a tamper track. If a tamper track is disrupted through the label 1401 being tampered, or if connection between a tamper track and the conducting path on the object 1402 is broken, the RFID function of the label 1401 may be modified in a manner as described above to indicate tampering. For example, if the label 1401 is applied to a cardboard box and the entire label and that part of the box the label is adhering to is cut out, tampering is indicated.

The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. The above-described embodiments of the invention may be modified or varied, and elements added or omitted, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.

Claims

ClaimsI claim:

1. A tamper indicating label comprising: an RFID layer providing an RFID function; an adhesive layer supporting the RFID layer; a destructible electrically conducting path sandwiched between the RFID layer and the adhesive layer, whereby the destructible conducting path is disrupted when the label is tampered, thereby modifying the RFID function of the RFID layer.

2. The tamper indicating label of claim 1 wherein the destructible conducting path is an RFID component.

3. The tamper indicating label of any of claims 1-2 wherein the destructible conducting path is connected to RFID components in the RFID layer.

4. The tamper indicating label of any of claims 1-2further comprising a pattern of an adhesion modifying coating between the RFID layer and the adhesive layer, the adhesion modifying coating modifying adhesion characteristics of the destructible conducting path.

5. The tamper indicating label of claim 4 wherein the pattern of the adhesion modifying coating includes at least two types of adhesion modifying coating.

6. The tamper indicating label of claim 4 wherein the adhesion modifying coating is printed on a bottom surface of the RFID layer and the destructible conducting path is formed on the adhesion modifying coating.

7. The tamper indicating label of any of claims 1-2 or 5-6 further comprising a visual tamper indicator arranged under the RFID layer and wherein the RFID layer is substantially transparent whereby the visual tamper indicator is visible.

8. The tamper indicating label of claim 7 wherein the visual tamper indicator is a colored layer and an adhesion-modifying substance is arranged between the RFID layer and the adhesive layer, the adhesion-modifying substance causing the colored layer to have different adhesion strengths with respect to the RFID layer and adhesive layer and thereby create a visual pattern on tampering of the label.

9. The tamper indicating label of any of claims 1-2, 5-6 or 8 wherein the RFID layer includes a memory chip and one of an antenna and an induction loop.

10. A tamper indicating label comprising: a substrate having RFID components and a destructible conducting path; and an adhesive layer supporting the substrate, at least a part of the destructible conducting path being in contact with the adhesive layer, whereby the destructible conducting path is modified if the label is at least partially removed from a surface to which it has been applied, thereby modifying RFID characteristics of the RFID components.

11. The tamper indicating label of claim 10 further comprising: a second conducting path formed on a top surface of the substrate and wherein the RFID components include an integrated circuit chip on the top surface of the substrate, the integrated circuit chip being connected to the second conducting path; and through-connects linking the second conducting path with the destructible conducting path, which is formed on a bottom surface of the substrate.

12. The tamper indicating label of claim 11 wherein the second conducting path and the destructible conducting path together form one of an antenna and an induction loop.

13. The tamper indicating label of any of claims 10 to 12 further comprising a top coating formed over the top surface of the substrate.

14. The tamper indicating label of any of claims 10 to 12 further comprising an adhesion-modifying coating between the substrate and the adhesive layer, the adhesion- modifying coating causing the adhesion strengths of the destructible conducting path to vary.

15. A security label for attachment to an object, comprising:

RFID components; means for attaching the RFID components to the object; a conducting path connected to the RFID components and contacting the means for attaching, the conducting path being broken when the label is tampered, thereby modifying the RFID characteristics of the label.

16. The security label of claim 15 further comprising a substrate supporting the RFID components and wherein the RFID components comprise a computer chip on a bottom surface of the substrate and the conducting path forms one of an antenna or an induction loop on the bottom surface of the substrate.

17. The security label of claim 15 further comprising: a substrate, the RFID components being formed on a top surface of the substrate; and connection points extending from the RFID components to a bottom of the substrate, wherein the conducting path is formed on a bottom of the substrate and connects the connection points.

18. The security label of claim 16 or 17 wherein the conducting path must be intact for the RFID components to operate.

19. The security label of claim 17 wherein the conducting path is a circuit functionally separate from the RFID components.

20. The security label of any of claims 17 or 19 wherein the conducting path is a track of conducting material formed in a pattern that extends around substantially the entire circumference of the bottom surface of the substrate.

21. The security label of claim 17wherein the RFID components include an induction loop and the conducting path is formed in series with the induction loop.

22. The security label of claim 17, wherein the conducting path forms an induction loop.

23. The security label of claim 15 further comprising: a substrate, the RFID components formed on a top surface of the substrate; and connection points extending from the RFID components to a bottom of the substrate, wherein a portion of the conducting path extends from each connection point to form an antenna.

24. The security label of claim 23 wherein the conducting path must be intact for the RFID components to operate.

25. A tamper indicating RF identification system, comprising: a substrate having a top and a bottom surface;

RFID components applied to the bottom surface of the substrate; a conductive layer applied in a pattern to the bottom surface of the substrate; an adhesive layer supporting the substrate such that the RFID electronic components and the conductive layer are sandwiched between the substrate and the adhesive layer, and wherein the adhesive layer, the substrate, and conductive layer have relative adhesion strengths such that when the system is partially removed from a surface to which it has been applied, at least one of the RFID components and the conductive layer is altered to modify the RFID characteristics of the system.

26. A security apparatus for indicating tampering, comprising: an object having a conducting path with at least two end points; a security label arranged on the object, the label comprising RFID components and a destructible conducting path between the RFID components and individual end points.

27. The apparatus of claim 26 wherein a connection between the end points and the RFID components via the destructible conducting path is necessary for the RFID components to function.

28. The apparatus of claim 26 or 27 wherein RFID components respond in a predetermined manner when a connection between the RFID components and end points is interrupted.

29. The combination of a security label and an object, wherein: the security label comprises:

RFID components; means for attaching the RFID components to the object; and destructible electronics connected to the RFID components, the destructible electronics being broken when the label is at least partially removed from the object; and the object comprises: a surface for receiving the security label; a conducting path having two ends, the ends of the conducting path being coupled to the destructible electronics thereby forming a circuit through the RFID components, the destructible electronics and the conducting path, whereby RFID characteristics of the RFID components are modified if the connection between the end points and the RFID components, via the destructible electronics, is broken.

30. A tamper indicating label, comprising: RFID components; means for attaching the RFID components to an object; and a tamper track connected to the RFID components, the tamper track being adapted to be damaged when the label is tampered and the RFID components being adapted to detect an interruption in the tamper track while maintaining their RFID capability.

31. The label of claim 30 wherein the tamper track is interrupted when the means for attaching is interfered with.

32. The label of any of claims 30 or 31 wherein the RFID components are active components.

33. The label of claim 32 wherein the RFID components test the tamper track and record data if the tamper track is interrupted.

34. The label of any of claims 30 and 31 wherein the RFID components are passive.

35. The label of any of claims 30 and 31 wherein the RFID components include only a memory chip.

36. The label of any of claims 30 to 31 wherein the memory chip is permanently altered when the interruption in the tamper track is detected.

37. A tamper indicating label, comprising: a substrate; an adhesive layer; a tamper track arranged between a first side of the substrate and the adhesive layer, portions of the tamper track having different adhering strengths to the substrate and the adhesive layer whereby the tamper track is disrupted when the label is tampered with; and an RFID chip arranged on a second side of the substrate and electrically connected to the tamper track via through connects in the substrate; the RFID chip being connected to other RFID components to provide an RFID function; the RFID chip detecting any disruption in the tamper track while maintaining its RFID function.

38. The label of claim 37, wherein the RFID chip is electrically connected to the tamper track via contact pads.

39. The label of claim 38, comprising two contact pads connected to the tamper track.

40. The label of any of claims 37 to 39, wherein the RFID chip is permanently altered when the tamper track is disrupted.

41. The label of any of claims 37 to39, further comprising one of an antenna and an induction loop formed on the second side of the substrate and connected to the RFID chip.

42. The label of claim 41 , wherein the one of the antenna and the induction loop are connected to the RFID chip via the two contact pads.

43. The label of any of claims 37 to 39wherein when the tamper track is interrupted the RFID chip is altered in a manner detectable by an RFID reading device so as to indicate the tamper track has been interrupted.

44. A tamper indicating label comprising: a substrate having first and second portions, the second portion being adapted to be looped back and connected to the first portion; an RFID transponder arranged on the substrate; a tamper track coupled to the RFID transponder and extending at least partially into the second portion of the substrate; an adhesive layer arranged on at least a part of the substrate in the second portion that contains the tamper track, the tamper track in that part of the substrate being adapted to be modified due to the relative adhesion strength of the tamper track when the label is tampered.

45. The label of claim 44 wherein the second portion is connected to the first portion in an area where either the RFID transponder or the tamper track is arranged.

46. The label of any of claims 44 and 45 wherein the adhesive layer is also arranged on the first portion of the substrate in an area where the second portion is connected.

47. The label of any of claims 44 to 45further comprising a bottom layer formed on regions of a bottom of the substrate where the adhesive layer is not present.

48. An RFID read/write apparatus, comprising: means for reading information from an RFID label; means for interpreting the information the information to determine if the label is tampered; and means for writing data to the label indicating the label is tampered if the information indicates the label is tampered.

49. The apparatus of claim 48 wherein the data is written permanently to a chip in the label.