FR2646260A1 - ADVANCED MICROCIRCUIT CARD READER - Google Patents

Abstract

The electronic microcircuit card reader comprises: - a slot LG housing, suitable for at least partially receiving said CM card and comprising a CO connector suitable for cooperating with the microcircuit MC of the card, and - connected electronic processing means MT to the CO connector. The housing LG is equipped with at least a first high frequency means acting by influence CA, placed between the slot FE and the connector CO, and the processing means MT comprise anti-fraud means comprising a second high frequency means GE acting by conduction, connected to said connector. The first and second high frequency means are one a generator, and the other a sensor. Means are also provided for deciding on the validity of the card as a function of a criterion depending on the signal perceived by said sensor.

Description

X.4 2646260

Advanced microcircuit card reader.

The invention relates to the processing of microcircuit cards,

also commonly called "smart cards" or "smart cards".

moire ". The invention applies advantageously but not limited to microcircuit cards which can be used in card readers.

cards for telephone devices with immediate or public payment

bliphones.

In such cards, the microcircuit is generally a

simple memory associated with wired logic. With the aim of ob-

hold a telephone call without paying the cost, the real card can be replaced by a simulator, namely a plastic card inserted into the card reader.

card and connected by wires to an appropriate electronic device.

prayed. To combat this type of fraud, some current card readers are fitted with mechanical devices such as shutters, the purpose of which is to isolate the card inserted into the reader from the outside. In principle, therefore, they prohibit the deporting of wires outside the reader. However, it is possible to use ultra-thin flexible wiring. In addition, a shutter is perceived by the user as an inconvenience because he is afraid of not being able to recover his card if the shutter is blocked.

The invention aims to provide a solution to this problem.

One Sut of the invention is to provide an anti-fraud card reader that does not require the use of devices

mechanical isolation of the card.

Another object of the invention is to provide such an anti-fraud device largely using the own constituents of the

card reader.

Another object of the invention is to produce such a device.

in a simple and inexpensive way.

The proposed electronic microcircuit card reader is of the type comprising: a slot housing suitable for at least partially receiving said card and comprising a suitable connector for cooperating with the microcircuit of the card; and

- electronic processing means connected to the connector.

According to a general characteristic of the invention, the housing is equipped with at least one first high-frequency means acting by influence, placed between the slot and the connector, and the

processing means include anti-fraud means comprising

ning a second high frequency medium, acting by conduction,

connected to the connector, the first and second high-frequency means

one being a generator, the other being a sensor, thus

as means to decide on the validity of the card based on

tion of a criterion depending on the signal perceived by said sensor.

The generator being in the processing means, it will apply

quer its high frequency signal between at least two of the connector terminals, preferably during power supply to the card. The sensor perceives, by inductive or capacitive influence, the effect of the resulting high frequency field

inside the card (or presumed to be so).

Conversely, the generator can apply the high frequency signal to the card (or presumed such) by influence

26-46260

inductive or capacitive. -The signal collected between two (at least) of the connector terminals represents the effect of the field

high frequency thus generated.

We will see later that it is possible, in this way, to

discriminate a real card from a simulated card, whose cables

bages will react differently to the high frequency signal.

Other advantages and characteristics of the invention appear

after examining the detailed description below and the

accompanying drawings, in which:

- Figure 1 is a general schematic block diagram of a first

mier embodiment of a card reader according to the invention

tion in which is inserted a memory card, - Figure 2 is a schematic block diagram detailing more precisely the processing means of the card reader of Figure 1, - Figure 3 illustrates schematically the configuration of a false card inserted in the housing of the card reader of Figure 1, and - Figure 4 schematically illustrates a second mode of

realization of a card reader according to the invention.

The drawings mainly contain character elements.

is certain. As such, they are an integral part of the

description and can not only be used to do better

understand the detailed description below but also contribute

buer, where appropriate, to the definition of the invention.

As illustrated in FIG. 1, an LC card reader, with which payphones are for example equipped, comprises an LG slot FE suitable for at least partially receiving a microcircuit card CM. Conventionally, this LG housing comprises, in a predetermined position, a CO connector, provided with electrical contacts (not shown here for the purposes of simplification) suitable for cooperating with the microcircuit.

MC from the CM card.

For the purposes of the present description, the term "connector" is

will therefore generate the connection element forming part of the reader

Map.

MV electronic processing means are connected to the connector.

CO tor in order to be able in particular to read the MC memory of the card, and to write therein, in cooperation with the logic

internal control of the card.

A first essential element of the invention consists of an AC electric and / or magnetic field sensor, such as a loop or a capacitor, arranged inside the LG housing.

between the FE slot and the CO connector. This AC sensor is equal-

ment connected to the MT processing means.

If we refer more particularly to Figure 2, we see that we conventionally find in the processing means

MT a UT processing unit intended specifically for

the memory card as well as the power supply means.

tion AL connected to the CO connector to deliver a con-

specific tinue for powering the memory card

re. Power supplies for writing or "programming"

tion "are not shown, as are the connections

logic and service to the connector.

Another essential element of the invention consists of methods

MAF anti-fraud yen located within the MT processing facilities. These include a high frequency signal generator, such as an oscillator, capable of applying an additional voltage between two wires or groups of wires of the connector.

high frequency of the order of a hundred milli-

volts and a frequency of the order of a few hundred megahertz. Thus, the generator GE acts simultaneously with the power supply means AL of the card reader and generates a high frequency signal at the level of the electrical contacts of the connector CO, which will therefore circulate in the card. This signal can be superimposed on one of the supply voltages

of the card, for example.

Another part of these anti-fraud means consists of

MD means intended to decide on the validity of the card inserted

picks up in the reader housing according to a criterion depending on the signal perceived by the sensor CA. To this end, these means MD comprise a high frequency amplifier AM connected to the output of the sensor CA, as well as a decision circuit

proper CD receiving the output signal of the amplifier

AM tor and connected to the processing unit UT.

To describe the operation of this card reader, reference will also be made to FIG. 3 which represents a false

FC card inserted in the LG slot, fitted with electric wires

triques leading on the one hand to the CO connector and connected to other

be part of an appropriate electronic device not shown

in this figure.

The principle of detection according to the invention is as follows.

The high frequency signal generated at the electrical contacts

The connectors of the connector introduce large and extensive current flows in the external connection wires FI. These then produce a "map" field detected by

the AC sensor.

In the case of the use of a real memory card, the electrical contacts of the connector being directly linked to the

microcircuit of the card, the "card" field is very low.

A simple comparison with a threshold therefore makes it possible to detect the

most frauds.

A variant of the invention consists essentially in modifying the role of the first and second high frequency means. This

variant is illustrated in Figure 4, in which the elements

elements similar or having functions similar to those represented

shown in Figure 2, have references assigned a sufficient

fixed v. Only the differences between these two figures will be described. The first high frequency medium, located in the housing, is here the GE-v generator, controlled by the UT-v processing unit, while the CA-v sensor (second high frequency medium) is incorporated into the MT processing means. -v. and connected to the CO-v connector to detect the "card" field. In other words, the outer connecting wires of a dummy card will act here as a "receiving antenna" while, in the first embodiment described above, they will act as a "transmitting antenna". In the second embodiment, when using a real smart card, no external wire is connected.

to the connector and the "card" field is then very weak.

Here again, a simple comparison with a threshold makes it possible to detect

most frauds.

To improve the detection of this "map" field, it is

advantageous to provide MB or MB-v shielding means (schematic

matically represented in FIGS. 2 and 4) intended to reduce the high frequency interaction between the first high frequency medium and at least part of the other constituents of the reader. This may result in a case of the high frequency link to the electrical contacts of the connector but also from parasitic high frequency disturbances originating from the processing means themselves, for example from the generator.

GE. A solution may consist, in the first embodiment

sation, in placing the MV processing means and the CO connector in an enclosure providing high frequency shielding. In order to further improve the decision-making capacity of the MD or MD-v means, it is advantageous that they have

a calibration state associated with the absence of a card in the compartment

ment and a working state associated with the presence of a card

in the accommodation.

The calibration state then makes it possible to define a reference threshold.

rence for the signal level perceived by the sensor so that any signal above the threshold is representative

of the presence of a false card in the slot. This stallion-

swimming thus makes it possible to minimize the effects of parasitic noise.

The presence of a card (true or false) in the slot can be determined by detection means such as a

photoelectric cell, placed in the vicinity of the entry slit

housing or by means arranged in the vicinity

connector or even by any other means.

The Applicant has also observed that the determination of the

threshold that can be used in the decision criterion could be obtained

naked by comparing the signal perceived by the sensor with the signal

high frequency generated at the connector itself.

This makes it possible in particular to overcome temperature problems.

ture and unwanted parasites.

It may also be possible to perform statistical measurements.

ticks and / or stochastics on the value of the signal perceived by the sensor in the presence of a card, so as to adjust the threshold

detection of a false card.

In this regard, the emitted high frequency signal is not necessary.

quite continuous. It can consist of a stiff pulse emitted at a regular rate, for example set by the processor of the processing unit UT or UT-v. The detection then consists, for this processor, in carrying out a correlation on the repetition of this pulse as detected, at the level of the sensor. In other words, it performs an integration restricted to the instants of emission of this stiff pulse,

which does not need to be modulated.

The invention therefore achieves in a simple and inexpensive manner a

anti-fraud device not requiring a mechanical device

isolation of the card and largely using the

existing components of a card reader.

The invention is not limited to the embodiments below.

described above but embraces all variants, including the following:

- one could conceive of superimposing the high frequency voltage

this to the write supply voltage of the card; the microcircuit card can be completely inserted into the housing; the invention applies to any card microcircuit as well as to any terminal other than payphones; - it is not necessarily imperative that the card be powered during the emission of the high frequency signal, in particular in the case where the generator is coupled by influence

à la carte.

It should also be noted that the device according to the

vention is not incompatible with the subject of the French Patent Application filed today in the name of the Applicant for

an "electronic coding device, in particular for publicity

ne ". For all intents and purposes, the content of this other Request

Patent Specification is incorporated into this specification.

Of course, some of the means described above can

be omitted in the variants where they are not used.

Claims (14)

Claims. 1. Electronic microcircuit card reader, of the standard type. taking: - slot housing (LG), suitable for at least partial reception - also said card (CM) and comprising a connector (CO) pro- pre to cooperate with the microcircuit (MC) of the card, and - electronic processing means (MT) connected to the connec- tor (CO), characterized in that the housing (LG) is equipped with at least a first high frequency means acting by influence (CA), placed between the slot (FE) and the connector (CO), and in that the processing means (MT) comprise anti-fraud means (MAF) comprising a second high frequency means (GE) acting by conduction, connected to said connector, the first and second high frequency means being one a generator, and the 'other a sensor, and means (MD) for deciding on the validity of the card as a function of a criterion depending on the perceived signal by said sensor. 2. Reader according to claim 1, characterized in that it comprises shielding means (MB) to reduce the high frequency interaction between the first high frequency means and a part at least of the other constituents of the reader. 3. Reader according to one of claims 1 and 2, characterized in that the decision criterion depends on the comparison between the signal perceived by the sensor and the high frequency signal generated. 4. Reader according to one of the preceding claims, character- ized in that the means for deciding (MD) have a calibration state associated with the absence of a card in the slot and a working state associated with the presence of a card in the slot. housing. 5. Reader according to one of the preceding claims, character- ized in that the first high frequency medium is a sensor while the second high frequency medium is a generator signal. 6. Reader according to claim 5, characterized in that the generator (GE) acts simultaneously with the supply means electrical connection (AL) of the card, located in the means treatment (MT). 7. Reader according to one of claims 5 and 6, charac- ized in that the generator comprises a high frequency oscillator capable of applying an additional high voltage frequency between at least two of the connector terminals. 8. Reader according to claim 7, characterized in that the frequency of the additional voltage is of the order of a few hundred megahertz. 9. Reader according to one of claims 7 and 8, characterized in that the level of the additional voltage is of the order of the hundred millivolts. 10. Reader according to one of claims 1 to 4, characterized in that the first high frequency medium is a generator while the second high frequency medium is a sensor. 11. Reader according to one of the preceding claims, charac- terized in that the high frequency signal generated by the generator is continuous. 12. Reader according to one of claims 1 to 10, characterized in that the high frequency signal generated by the generator comprises a succession of pulses. 13. Reader according to claim 12, characterized in that the decision criterion depends on a correlation, carried out at sensor level, on repetition of this pulse. 14. Reader according to one of the preceding claims, charac- terized in that the means for deciding (MD) comprises a high frequency amplifier (AM) connected to the output of the sensor (CA).