GB2510127A

GB2510127A - Security device for a contactless card

Info

Publication number: GB2510127A
Application number: GB201301251A
Authority: GB
Inventors: James Churchman
Original assignee: SMALL PLANET TECHNOLOGY Ltd
Current assignee: SMALL PLANET TECHNOLOGY Ltd
Priority date: 2013-01-24
Filing date: 2013-01-24
Publication date: 2014-07-30
Also published as: GB201301251D0

Abstract

A card 1, or card holding device, for keeping in close proximity with a contactless data card, such as a smartcard. The card/device be kept in the same wallet or purse as the smart card. The card/device provides a means of reducing the responsiveness of the smartcard to the field generated by a contactless card terminal, or reader. The aim is to prevent fraudulent reading of the smartcard. The card/device comprises magnetic material 4 which shifts the resonant frequency of the smartcards antenna circuit. The card/device also comprises an active circuit 2,3 for recovering energy from the readers field and using it to generate false data to interfere with, or jam, the communication between the card and the reader terminal. These two techniques could be used individually or in combination.

Description

Contactiess Card Security Device This invention relates to a device to prevent the reading of a contactless smart card either by accident or with intent to obtain data or perform transactions with fraudulent or other criminal intent.

Financial institutions such as banks and other organisations such as larger retailers are issuing smart cards (credit cards) debit cards, store cards) with contactless capability. These cards generally operate in accordance with the specification ISO/1EC14443. To make a contactless transaction, the user places the card within a short distance of the antenna of the PCD (this is what lS0/1EC1443 calls the card reader or terminal. It stands for Proximity Coupling Device). The distance involved is typically 10cm or less. Data is exchanged between the card (or P1CC as lS0/1EC1443 calls it) and the PCD and a financial transaction may result without the need for further action on the part of the card holder. The problem with these cards is that they are often kept in wallets or purses and are vulnerable, particularly in crowded public places, to being read by portable PCDs, the data gathered being used for criminal purposes. A fraudster need only bring a portable PCD within range of a valid card while it remains in the wallet or purse of the card holder for it to be read. It is worth noting that the PCD need not be provided by a "legitimate" provider. Silicon integrated circuits are readily available that make the construction of an "unofficial" PCD relatively easy for someone with the right skills. Such a device would not need to go through the time consuming and expensive process of certification and could even have properties that make it un-certifiable but increase its utility to a fraudster, such as increased field intensity allowing card reading at a slightly greater range. There are on the market, "screened wallets" that purport to provide an effective defence against such attack by incorporating conductive (metal) flexible screens. Whilst such devices may provide some degree of protection they can't provide a complete shield from the field of an "unofficial" PCD since they do not provide a complete connected metal shield (faraday cage) all around the card and the presence of other bulky items (bank notes, coins, keys etc.) may well hold the wallet or purse open enough to allow attack, particularly ifa higher power device (PCD) is used. Also, repeated opening and closing is likely to degrade the screening.

To overcome this, the present invention, a Card Security Device (CSD) provides a suitably sized card or card holder, incorporating (ideally encapsulated within the card) a quantity of magnetic material with a relative permeability (at the carrier frequency used) significantly different to the value 1, designed to alter the effective value of the P1CC loop antenna inductance and thus move its resonant frequency (tuning) away from the fixed carrier frequency used by the.PCD or an antenna and electronic circuits designed to operate at the PCD carrier frequency and capable of modulating the field intensity in a similar manner to that used within a typical P1CC, or both in which case the tuning of the CSD antenna will take into account the presence of the magnetic material. The CSD is placed within the wallet or purse that also contains the P1CC. In the presence of the field from a F'CD the CSD will either have shifted the tuning of the P1CC such that it is unresponsive to the PCD or it is activated, receiving power from the PCD field that might otherwise have been available to power the P1CC and additionally generate false data to interfere with and prevent the reading of data or a combination of these effects to provide protection from unauthorised reading of the PCD data.

One advantage of this invention is that protection for contactiess card can be provided in existing wallets, purses, bags etc. Another is that it does not depend on the integrity of a complete conductive screen (faraday cage) around the cards which is likely to be compromised if other bulky items are carried or with continual use or particularly in the case of more rigid metal screens, prove inconvenient to use.

The invention will now be described solely by way of example and with reference to the accompanying drawing which shows the CSD in the form of a plastic card whose physical size complies with the requirements of ISO/IEC 7810, defining the size of a standard credit card.

In the drawing Figure 1, item 1 shows the outline of the plastic card to lSO/IEC 7810. Item 2 is the antenna designed to resonate at the frequency of operation of the P1CC (carrier frequency 13.56MHz), this antenna being embedded within the plastic card as is done on standard P1CC cards.

Item 3 is the electronic circuit also embedded within the card that extracts power from the field and may also modulate the field by varying the load on the antenna. Item 4 is the magnetic material (typically ferrite) that is provided to move the resonance of the P1CC receiving antenna thereby making the P1CC unresponsive. This is not the only possible position for the magnetic material nor need it be one single piece. Figure 2 shows the two modulation schemes used by ISO/IEC 14443 cards for P1CC to PCD communications, one being the on off keying of a subcarrier and the other using a phase shift keyed subcarrier. Figure 3 shows a combination of the two schemes such as could be generated by the CSD to ensure maximum disruption of communications between any nearby P1CC and the PCD The loop antenna on the CSD is designed to resonate at the carrier frequency (13.56MHz for ISO/IEC 14443 cards). The presence of ferrite or other magnetic material is taken into account when tuning this antenna. The electronic circuit is designed to absorb power from the field created by the PCD which would otherwise be available to a nearby P1CC. It uses the power available to generate a data stream that is used to vary the loading on the CSD antenna circuit thereby modulating the field amplitude with the data stream. With a CSD near a P1CC, the P1CC is detuned such that it is less responsive to a field generated by a PCD. This field will power up the CSD which will generate a stream of meaningless data and will modulate the field with a combined FSK/PSK scheme such as is shown in Figure 3 to interfere with any communication between the P1CC and the PCD. The CSD generated data will start as soon as a suitable field is encountered and will continue whilst the field amplitude is sufficient.

Claims

Claims 1. A card or card holding device (Card Security Devise or CSD)that being placed in close proximity to a contactiess smart card that prevents the card data being read by a contactiess terminal (PCD) by introducing magnetic material with a relative permeability significantly different to unity to shift the resonant frequency of the protected card's loop antenna circuit rendering it less responsive to the field and by active electronic means whereby power is recovered from the PCD via a loop antenna on the CSD, these techniques being used either separately or in combination.
2. A CSD as in Claim 1 in which the recovered power is used by the electronic circuit to generate a data stream that is used to modulate the field amplitude to interfere with any data from the protected smart card.
3. A CSD as in Claims 1 and 2 in which the CSD loop antenna system is tuned to the carrierfrequency used by the field generating PCD
4. A CSD as in Claims 1,2 and 3 in which the carrier frequency is 13.56MHz
5. A CSD as in Claims land 2 inwhich the modulated signal from the CSD uses a subcarrier
6. A CSD as in Claim 5 in which the subcarrier 847.5kHz
7. A CSD as in Claims 1 and 2 in which the data from the CSD is modulated as a combination of on/off keyed subcarrier and phase shift keyed subcarrier as shown in Figure 3.& A CSD as in Claim 1 in which the magnetic material used has a high relative permeability at the carrier frequency used to communicate between the PCD and the protected cards.9. ACSD as in Claim land Claims where the magnetic material is positioned to overlap the P1CC coil antenna when the CSD and the P1CC are placed side by side to increase the effective "De-tuning" of the P1CC.10. A CSD as in Claim land ClaimS whereby multiple pieces of magnetic material used 11. A CSD as in ClaimS or Claim 9 or Claim lOin which the carrier frequency is 13.56MHz