GB2525235A

GB2525235A - Means for recovering tamper evidence in RFID tags regardless of the power supply to the chip or reconnection of the tamper loop.

Info

Publication number: GB2525235A
Application number: GB1406940.5A
Authority: GB
Inventors: David Bernard Mapleston
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-04-17
Filing date: 2014-04-17
Publication date: 2015-10-21
Anticipated expiration: 2034-04-17
Also published as: GB201406940D0; GB2525235B

Abstract

An RFID tag which indicates that a tamper event has occurred includes a memory cell 1 connected to a conductive loop 6 by pins 12. The memory cell has a memory status set to '1' and contains a charge 2 which dissipates via the conductive loop 6 as a result of a tamper event. When the charge dissipates the memory status changes to '0'. Upon being interrogated by a reader, the tag sends memory status information to the reader thus indicating whether the tag has been tampered with. Preferably the conductive loop 6 includes a switch 5 which is closed when the tag is tampered with, causing dissipation of the memory cell charge. Alternatively, the conductive loop may be a closed circuit (not shown) which is opened as a result of tampering. A diode 4 prevents the memory cell from being reset by reconnecting or repairing the tamper circuit. A diode 9 prevents the cell from discharging when the voltage from the power supply 3 falls below a useful level. The tag may be used to indicate when the contents of a bottle have been tampered with.

Description

Long Range UHF RFID Tag with non powered anti tamper means Terms used: Tag: two paper thin printed antennas or capacitors with an integrated circuit chip between the two to form a radio transponder device.

Chip: the black dot in the middle of the tag, this is the integrated circuit that provides the backscatter of the radio power from the interrogator; it also deals with all the communication and memory data. In this case it also handles the logic state and memory for tamper evidence like a bottle capsule cover removal or lid removal.

Interrogator or Reader: A tag reader; this bounces a radio signal off the tags which modulates the reflected signal and hence reports back the tag serial number and other data back to the interrogator.

Tamper evidence: is a means for showing that an item has previously been opened or disturbed, bottle top capsule removal for example.

Background information:

Many HFID tags on the market today can display tampering; these tags are carefully designed so that the tamper loop cannot be mended economically by the user or fake trader.

Tags with electronic tamper evidence are also common in the marketplace; however, these all have a major flaw which is addressed by this invention.

The problem addressed by this invention is both serious and costly, for example the purchaser or trader collects empty bottles or containers and has the equipment to rework the seal, so that the product looks and acts like the original tagged item.

What is now required is an electronic tamper evident chip which can record and memorise the tampering event even though the tag and packaging have been perfectly repaired.

No UHF tags can be found on the market today which fully solves this issue and fulfils this need for unpowered tamper evident memory.

Tag suppliers offer tamper evidence; however, the tags require power from the Header when the tamper occurs to save the tamper event into memory. If the tamper event occurs when the tag is not powered by a battery or external RF field, the tag has no means of reporting this occurrence at a later time; especially if the tamper loop is perfectly repaired.

For example, a bottle of spirit which has previously been used could be filled with inferior spirit, the tag could then be repaired and placed back on the bottle; the bottle could then be resold at the quality price with inferior or even dangerous spirit inside. This patent avoids this scenario by permanently recording the tamper event, even when power is not applied to the tag; the tag retains the knowledge that the loop has be broken and re connected or in the embodiment described connected and re opened.

Some tags claim this type of security; however, it is very simple for a black market operator to overcome the damage and then re program the tag with its original data content.

Embodiment: Figure 1 shows one of a plurality of embodiments for this anti tamper tagging chip addition.

The tag itself would have three primary components, the antenna, the RFID chip and the tamper loop. This loop can be any conductive material which, in this embodiment, would be a normally open loop.

The storage device Figi,1 could be any of a plurality of charge storage means. The most likely would be a simple non volatile memory cell; however, other embodiments could be used like ferrite or ferroelectric memories to hold the necessary energy until the tag is re powered and read by the interrogator.

External memory devices could be used such as super-capacitor or even battery type chemical cells.

In this embodiment The memory cell is set to The al' sTale by the charging circuiT formed by field elf oct transistor figl 10 and diode tigl 9. The memory cell can only be charged when the device is powered by same means; this is usually the RF field from the interrogator. Diode Figl,9 represents the circuit which prevenTs the memory cell from discharging when the supply figl,3 falls below a useful levol.

The field effect transistor gate figi,8 gives the devices internal logic a means of disabling or enabling this memory function for example when the function is controlled by an internal password match, or simple enable bit.

Figi,l I and figi,7 represent the means of reading the cell when power is re-established to the chip.

Tho cell figuro 1,1 is filled with chargo, shown pictorially by figl,2; this charge remains in tho cell regardless of the voltage at VCC figi 3. At any time regardless of the voltage at VCC the charge can be removed by The loop circuit figure 16. The instant the Tamper switch figl,5 closes the charge will be removed from the memory cell changing it to a.0, state.

The tamper loop is external to the device and connected to device pins, or pads, shown as fig 1,12 The diode figl,4 represents the circuit which stops the fraudster from re-charging the cell from an external voltage.

Each block in the pictorial embodiment of this invention, figl, is a standard known and well used electronic component or circuit.

Remarks: The advent of this invention has been driven by the recent breakthroughs in tagging bottles for authenticity, traceability and stocktaking.

Due Ta this RFID breakthrough, It is now cost effective to protect bottles and oTher items in the supply chain whilst they are away from the readers/interrogator. A tag that is either dead or unreadable or signals the tampering with a bit change in the data, to indicate that the container has been ill treated or opened is of great benefit. Doing this whilst the tag is away from the reader power is difficult but now possible using modern memory cells in embodiments like the one described in this patent.

Obviously the tampering is only seen when the tag is interrogated; however, the fact that re connecting the tamper loop will not re establish a no tamper signal from the tag is a vast improvement aver current tamper evident tags.

Tags already oxist whero tamper evidence can be detected; however, all of these require powor at the point of tampering, unless powered they immediately forget the tamper event unless the tamper loop is left in the obvious tamper state.

Fixing tho tamper loop and replacing the capsulo is a very profitable businoss in thc fine wine, spirit and Pharmaceutical industries due to high demand and high taxation; this patent gives us another step forward in the baTtle against the counterfeiters, smugglers and black market traders.

Claims

CLAIMS1. A tamper evident RFID tag as described in this invention where the tamper detection event is memorised by the tag when the tag is not powered by a reader/interrogator or any other means.
2. A tamper evident tag as described in claim 1 where the memory of the tamper event tag cannot be cleared or reset by any form of re connection or repair of the tamper detection loop or circuit.
3. A tamper evident tag as described in all above claims where the tamper means is a conductive loop which is made closed circuit by a tampering event.
4. A tamper evident tag as described in claim 1 and 2 where the tamper means is a conductive loop which is made open circuit by some tampering event.
5. A tamper evident tag as described in claim 1 and 2 where the tamper event is determined by the change in property of an external transducer or any interfacing means between the said transducer and the chip.
6. A tamper evident tag as in all claims where the tamper evident means is memorised using a charge storage cell or energy storage device of any type.
7. A tamper evident tag as in claim 1 where the external tamper loop charges or discharges a memory cell either directly or through other electronic components.
8. A tag embodiment as in the description and claim 1 where the tag still contains evidence of a tamper event although the tamper event occurred when the device was powered or not powered by the reader/interrogator or other means.
9. A tag structure as in all above claims where the memory cell is an external charge storage device such as an external non volatile memory, super capacitor or chemical battery.
1@.A tamper evident tag where the tamper evident memory can only be reset from within the tags chip.
11.A tamper evident tag embodiment as described in all claims where the resetting of the tamper evident memory is password protected by some means within the chip.