Smart card.
The smart card uses galvanic resistive buttons for authentication and device activation, addressing the complexity and cost of biometric solutions, enhancing security and efficiency in contactless payments.
Patent Information
- Application Number
- FR2022001707
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-02-26
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2042-02-26
AI Technical Summary
Existing smart cards, particularly in the banking sector, face challenges with complex and costly biometric solutions for secure contactless payments, which require additional electronics and have reliability concerns.
A smart card design incorporating galvanic resistive buttons on the surface, allowing direct physical contact between the user's skin and conductive tracks to form closed circuits, which are used for authentication and to selectively activate electronic devices, including a microcontroller to verify a secret code.
Provides a cost-effective and reliable authentication method that enhances security for contactless payments by using galvanic resistive buttons, optimizing energy consumption and simplifying implementation.
Smart Images
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Abstract
Description
Title of the invention: Smart card.
[0001] The present invention relates to the field of smart cards.
[0002]
[0003] A smart card is a card made of plastic, paper, cardboard or metal, the dimensions of which are defined, for example, according to a so-called ID1 format, in particular in accordance with the ISO / IEC 7810 standard, and which carries at least one chip capable of containing information about its bearer.
[0004]
[0005] The chip of a smart card is an integrated circuit which most often contains a microcontroller and a set of at least one memory, for example a non-volatile memory, typically a read-only memory (ROM), a volatile memory, typically a random access memory (RAM), and / or a storage memory, typically of the EEPROM or Flash type.
[0006]
[0007] As is known per se, the uses of smart cards are varied. These are for example used as an official (state) means of personal identification, for example as an identity card, driving license, health insurance card, etc. or as a private means of identification, for example as an access badge, subscription card, etc.
[0008]
[0009] As is well known, smart cards are also used as a means of payment (bank card, electronic wallet). The banking sector being particularly restrictive in terms of security, for the sake of brevity, it will be the only one described here.
[0010]
[0011] Payment by bank card most often requires the use of a PIN code.
[0012]
[0013] Once placed on the market, an enrollment step is performed. In this enrollment step, the PIN code is either assigned to the user or defined by the user. After this enrollment step, the chip of a smart card can only be read.
[0014]
[0015] Reading can be implemented by physical contact in a reader, thanks to a set of tips which come into contact with the chip, for example in a banknote dispenser.
[0016]
[0017] Reading the chip can also be implemented without physical contact, by radio waves, most often radio frequency. This contactless mode is also known by the acronym NFC for Near Field Communication.
[0018]
[0019] Some dual chip cards can be read by contact and contactless.
[0020]
[0021] Since a smart card is used for applications considered potentially sensitive, it is useful to establish a certain number of security elements.
[0022]
[0023] In this respect, it is known to implement a set of at least one authentication factor.
[0024]
[0025] An authentication factor is a physical, cognitive, or biological factor that allows a user to be authenticated by a computer system.
[0026]
[0027] There are different authentication factors:
[0028]
[0029] Memory factors (what the wearer knows).
[0030] For example, information that he has memorized, typically a password or a PIN code for a bank card.
[0031]
[0032] Material factors (what the wearer owns).
[0033] For example a USB key, a smart card.
[0034]
[0035] Bodily factors (what the wearer is).
[0036] For example a fingerprint, or more generally a biometric.
[0037]
[0038] Depending on the number of authentication factors implemented, a distinction is made between simple authentication, which uses only one factor, and strong authentication, which requires the concatenation of at least two authentication factors.
[0039]
[0040] In the field of banking identification, for example the European directive DSP2 (article 4, definition 30 accessible at the address https: / / eur-lex.europa.eu / legal-content / FR / TXT / HTML / ?uri=CELEX:32015L2366&fr om=FR) sets out the rules for strong authentication.
[0041]
[0042] The present invention is placed in particular in the field of strong authentication, but is not limited thereto, as described later.
[0044] In this field, new bank cards known as "biometric" are known in which a fingerprint reader is integrated into the bank card.
[0045]
[0046] Biometrics allows contactless payment to be authorized and can sometimes replace the use of the PIN code.
[0047]
[0048] However, such smart cards are complex, expensive products, with a lot of new, additional electronics, which is linked to biometrics and whose reliability has yet to be established.
[0049]
[0050] The present invention aims to propose a clever and simpler to implement strong authentication solution, thanks to galvanic resistive buttons, involving direct physical contact between the skin of a user, in this case the card holder, and two contact pads of conductive tracks, the conductivity of the skin making it possible to close the electrical circuit between the two contact pads, and which are distinguished from the resistive buttons used in resistive touch screens, capacitive buttons, mechanical buttons or even optical buttons.
[0051]
[0052] In this context, the present invention relates to a smart card (100) comprising:
[0053] - a first external layer (110) forming an upper face
[0054] - a second external layer (120) forming a lower face,
[0055] - an insert (130) comprising a first electronic circuit forming an antenna (131) to communicate with a card reader, the insert being sandwiched between the two outer layers,
[0056] - a secure element which is configured to be supplied with electrical energy by the antenna (131) and may include an individual code (PIN) in a memory, and
[0057] - a microcontroller (140).
[0058]
[0059] It is essentially characterized in that:
[0060] - the smart card (100) further comprises a second electronic circuit in electrical connection with the microcontroller (140), and distinct, independent, from the first electronic circuit;
[0061] - said second electronic circuit comprising a set of pairs (160) of contact pads, accessible from the outside of the smart card (100), each pair (160) of contact pads forming a galvanic resistive button having a switch function, the switch being open by default and closed upon physical contact between the pads of said pair and the skin of a user.
[0063] It can be provided that the secure element comprises a microcontroller (140); and in which:
[0064] - either the microcontroller (140) and the microcontroller of the secure element are the same,
[0065] - either the microcontroller (140) is distinct from the microcontroller of the secure element.
[0066]
[0067] It can be provided that the pairs (160) of contact pads are arranged on at least one of:
[0068] - at least one slice of the card (100);
[0069] - at least one face of the card (100).
[0070]
[0071] It can be predicted that:
[0072] - the second electronic circuit comprising the set of pairs (160) of pads of contact is arranged on the insert (130) comprising the first electronic circuit forming the antenna (131), or
[0073] - the second electronic circuit comprising the set of pairs (160) of pads of contact is arranged on an insert (170) separate from the insert (130) comprising the first electronic circuit forming the antenna (131);
[0074] the pairs (160) of contact pads being formed:
[0075] - by cutting the conductive tracks (150) of the insert (170) supporting the second electronic circuit;
[0076] - by folding back on itself the insert (170) supporting the second electrical circuit electronics; or
[0077] - by electrical tracks (150) possibly locally widened or thickened in the form of connection pads, and accessible via a recess (111) in the first external layer (110) or the second external layer (120) of the card (100), opening onto the insert comprising said electrical tracks of the second electronic circuit.
[0078]
[0079] It can be provided that the second electronic circuit comprising the set of pairs (160) of contact pads is arranged on an insert (170) separate from the insert (130) comprising the first electronic circuit forming the antenna (131); the card (100) further comprising a metal plate, arranged between the two external layers or on the edge of the card (100),
[0080] the second electronic circuit comprising a set of pairs (160) of contact pads being machined in said metal plate.
[0081]
[0082] It is also possible to provide at least one of the electronic devices among:
[0083] - a display device,
[0084] - a sound device,
[0085] - a biometric sensor,
[0086] - a memory,
[0087] - a battery;
[0088] each electronic device being in electrical connection with the microcontroller (140) via at least one respective pair (160) of contact pads forming a galvanic resistive button having a switch function, the closing of a switch making it possible to selectively activate the corresponding device.
[0089]
[0090] It is also possible to provide:
[0091] - a memory in which a secret code is recorded, which is a binary code ac transferable to the microcontroller (140), the secret code being pre-assigned to the user of the smart card (100) or predefined by the latter in an enrollment step;
[0092] and in which the microcontroller (140) is configured to:
[0093] * detect the closing of each switch during physical contact between a pair (160) of contact pads with the skin of a user;
[0094] * calculate the code which corresponds to the state of opening or closing of the assembly switches,
[0095] * compare the calculated code to the recorded secret code, and
[0096] * emit a signal which is a function of the result of the comparison.
[0097]
[0098] It can be predicted that:
[0099] the microcontroller (140) is configured to be indifferent to the order of closing of the set of switches, so that the calculated code and the secret code are a combination.
[0100]
[0101] It can be predicted that:
[0102] the microcontroller (140) is configured to determine the closing order of the set of switches, so that the calculated code and the secret code are an arrangement.
[0103]
[0104] It is also possible to provide:
[0105] - a timer, in electrical connection with the microcontroller (140);
[0106] and in which:
[0107] - the microcontroller (140) is further configured to calculate the delay between the closing of a switch and the closing of the switch which follows it;
[0108] the calculated code and the secret code being a function of the closing time between two inter- consecutive breakers.
[0109]
[0110] It can be provided that the current between the set of pairs of contact pads and the microcontroller (140) is a direct current or an alternating current. [YES]
[0112] It can be provided that the chip card (100) is a bank card, in which the microcontroller (140) is configured to issue a contactless payment authorization if the calculated code is identical to the secret code.
[0113]
[0114] Other characteristics and advantages of the present invention will appear more clearly on reading the following description given by way of illustrative and non-limiting example and made with reference to the appended figures.
[0115] The figures are purely illustrative and are not to scale.
[0116] [Fig-1] illustrates an exploded view of an embodiment of a smart card according to the invention, comprising two inserts and in which the contact pads are accessible from the 4 edges of the card,
[0117] [Fig.2] illustrates a section in the XOZ plane of the dotted area of [Fig. 1],
[0118] [Fig.3] illustrates an exploded view of an embodiment of a smart card according to the invention, comprising a single insert and in which the contact pads are accessible from an external face,
[0119] [Fig.4] illustrates an exploded view of an embodiment of a smart card according to the invention, comprising a metal plate formed of 4 segments and in which the contact pads are accessible from the 4 edges of the card,
[0120] [Fig.5] illustrates an exploded view of an embodiment of a smart card according to the invention, comprising two inserts, in which the solid arrows indicate the folding of the conductive tracks on the insert supporting the second electronic circuit,
[0121] [Fig.ôA] illustrates a section in the YOZ plane of [Fig.5], further comprising a covering layer between the 2 inserts,
[0122] [Fig.ôB] illustrates in exploded view a section in the YOZ plane of [Fig.5], in which the antenna tracks are covered with an electrically insulating varnish,
[0123] [Fig.ôC] illustrates in exploded view a section in the YOZ plane of [Fig.5], in which the electrical tracks of the insert supporting the antenna and the conductive tracks of the second electronic circuit are arranged so as not to overlap,
[0124] [Fig.7] illustrates an embodiment of a smart card according to the invention, in in which the contact pads are accessible from one side and one edge of the card,
[0125] [Fig.8] illustrates an exploded cross-section in the XOZ plane of the map of [Fig.7].
[0126] Detailed description
[0127] For brevity, a smart card 100 is referred to as a “card”.
[0128] Also for brevity, only the case of a bank card, which is particularly restrictive due to security standards, will be described here. The bank card can be a debit card, a credit card or a debit / credit card.
[0129] The bank card is at least contactless and can be dual, i.e. contactless and contact.
[0130] For brevity, only a contactless payment bank card will be described here.
[0131] To date, for example, in Europe there is a threshold value below which a payment with such a card is automatically authorized, which can cause problems in the event of theft or loss of the card, and therefore fraudulent use of the card.
[0132] To remedy this problem, it appears useful to be able to implement strong authentication, as detailed later, for example to reinforce the security of payment for small values, or to authorize the payment of larger values while remaining in contactless mode.
[0133]
[0134] * Smart card *
[0135] A card 100 according to the invention comprises, like known cards, an antenna 131 sandwiched between a first external layer 110 and a second external layer 120,
[0136] A first outer layer 110, for example made of plastic, in this case PVC, PC or PET, which is hot-laminated, forms an upper face, and a second outer layer 120, for example also made of plastic, forms a lower face. There are also outer layers made of paper or metal.
[0137] The antenna 131 is arranged on an insert 130 supporting the antenna. It is configured to communicate with a card reader.
[0138] An insert, or pre-laminate, also known by the Anglicism "inlay", is a flat layer of plastic, generally PET, in the form of a film or sheet, which comprises a layer of conductive metal, generally copper or aluminum or a copper- or aluminum-based alloy, arranged on at least one of the faces of the plastic layer.
[0139] The conductive metal layer of the insert 130 is masked and then chemically etched to create a first electronic circuit. When the insert 130 comprises a conductive metal layer per face, mechanical connections (vias) can be created between the two metal layers to electrically connect the two layers of metal.
[0140] In a known manner, the conductive metal layer of the insert 130 can also be produced by continuous deposition of a conductive metal wire, generally copper or copper-based, to produce the antenna 131.
[0141] Such inserts 130 are used to manufacture antennas 131 which go into cards 100, but also into identity documents, etc.
[0142] For the purposes of the present invention, “first electronic circuit” means the electronic circuit of the insert 130 supporting the antenna 131.
[0143]
[0144] * Secure Element *
[0145] The card 100 also includes a secure element (not shown), which generally includes a microcontroller.
[0146] The secure element is configured to be supplied with electrical energy by the antenna 131, in this case using a micro-antenna 132 coupled to the antenna 131 of the card 100.
[0147] The secure element may comprise an individual code (PIN) recorded in a memory after an enrollment step.
[0148]
[0149] In operation, the antenna 131 makes it possible to recover the energy from the reader by inductive coupling, to distribute it to the secure element using the micro-antenna 132.
[0150]
[0151] Typically during a transaction, for example a cash withdrawal from a bank ATM or a contactless payment, the cardholder 100 enters his PIN code. This entered PIN code is sent to the microcontroller of the secure element which compares this entered code with the PIN code stored in its memory, and if the two codes are identical then the secure element authorizes the transaction.
[0152] The present invention adds the following elements to the state-of-the-art cards described above.
[0153]
[0154] * Microcontroller 140 *
[0155] According to the invention, the card 100 comprises a microcontroller 140.
[0156] In a first variant, it is provided that the card 100 comprises only a single microcontroller, that of the secure element, and which is configured as described later.
[0157] In a second variant, it is provided that the card 100 comprises two microcontrollers: the microcontroller of the secure element, and a second microcontroller 140, distinct from the microcontroller of the secure element, and which is configured as described later. In this variant, the second microcontroller 140 is in electrical contact with the microcontroller of the secure element.
[0158] By conciseness of these two variants, we mean hereinafter “the” or “a” microcontroller, and the drawings only represent a microcontroller bearing the single numerical reference 140.
[0159]
[0160] * Contact pads *
[0161] According to the invention, it is provided that the card 100 comprises a set of pairs of contact pads, grouped in pairs 160.
[0162] Each pair of contact pads 160 is accessible from outside the card 100.
[0163] Each pair of contact pads 160 forms a galvanic resistive button which has a switch function within a second electronic circuit which is electrically connected to the microcontroller 140.
[0164] Therefore, within the meaning of the present invention, we consider indistinctly “switch”, “pair of contact pads 160” and “button”.
[0165] The second electronic circuit is distinct, independent, from the first electronic circuit which supports the antenna 131.
[0166] However, in a first variant, the second electronic circuit is arranged on the same insert 130 as that comprising the first electronic circuit forming the antenna 131.
[0167] In a second variant, the second electronic circuit is arranged on another insert 170 than the insert 130 comprising the first electronic circuit forming the antenna 131.
[0168] The second electronic circuit comprises conductive tracks 150, in this case made of aluminum.
[0169] In this case, the contact pads of a pair 160 are distant from each other so that the contact of a finger on a pair of contact pads 160 is sufficient to close the corresponding switch, thanks to the conductivity of the skin of a user or of the card holder 100. Preferably, it is provided that two adjacent contact pads of the same pair are distant from each other by at least 20 μm.
[0170] Preferably, it is provided that two adjacent pairs of contact pads are spaced from each other by at least 10 mm, so that closing one switch with a finger does not close the adjacent switch with the same finger.
[0171]
[0172] It can be provided that the card 100 comprises at least one of the electronic devices among: - a display device, - a sound device, - a biometric sensor, - a memory, - a battery - etc.
[0173] Preferably in this case, each electronic device is in electrical connection with the microcontroller 140 via at least one respective pair 160 of contact pads forming a galvanic resistive button having a switch function.
[0174] Thus, closing a switch makes it possible to selectively activate the corresponding electronic device.
[0175] Thanks to this configuration, energy management is optimized, in particular for electronic devices operating on battery, since the electronic devices only consume energy when the corresponding switch of the electronic circuit is closed.
[0176] Indeed, a card 100 comprises for example a biometric sensor. By default the switch of the electronic circuit corresponding to said biometric sensor is open, so it does not consume energy.
[0177] If the cardholder 100 closes the corresponding switch with his finger or hand, then the electronic circuit comprising said biometric sensor can be supplied with electrical energy via the antenna 131, when the card 100 is in the magnetic field of a card reader.
[0178] In the same way, it is possible for example to power a display screen, charge a battery, read a memory or write to it, etc.
[0179]
[0180] * Position of the pairs of contact pads *
[0181] The pairs 160 of contact pads are arranged on at least one of: - a slice of card 100; - one side of card 100.
[0182] For example, switches can be provided on one or more edges of the card 100, depending on the ergonomics and the desired level of security.
[0183] It is also possible, as an alternative or in addition, to provide switches on the upper face, on the lower face, or on both faces of the card 100.
[0184] For example, a card 100 may include switches on both sides of the card 100 and on the edge. The switches on both sides may be activated by pinching the card 100 and the switches on the edge(s) may be activated by the index finger and little finger of one hand, or using two hands.
[0185]
[0186] * Manufacturing of pairs of contact pads *
[0187] According to a first embodiment, the pairs 160 of contact pads are accessible by at least one edge of the card 100.
[0188] In a first variant, the pairs 160 of contact pads, identified by dashed lines in [Fig.l] and in [Fig.2], are formed by cutting the conductive tracks 150 of the insert 170 supporting the second electronic circuit, as illustrated in [Fig.l]. In this case, the conductive tracks 150 open onto the edge of the card 100. The end of the conductive tracks 150 forms the contact pads. In [Fig.2], 3 pairs 160 of contact pads are shown.
[0189] Preferably, the electrical tracks 150 of the second electronic circuit are cut simultaneously with the cutting of the first external layer 110 forming an upper face and of the second external layer 120 forming a lower face, and for example with a punch.
[0190] In this case, the second electronic circuit comprising the set of pairs 160 of contact pads is preferably arranged on an insert 170 separate from the insert 130 comprising the first electronic circuit forming the antenna 131.
[0191] It is possible to locally increase the width or thickness of the metal layer at the edge of the card 100 to manufacture a contact pad.
[0192] In a second variant, the pairs 160 of contact pads are formed either by folding the insert 170 supporting the second electronic circuit back on itself; or, as illustrated in [Fig.5], by folding the conductive tracks 150 of the second electronic circuit under the flat plastic layer of the insert 170, at the edge of the card 100, before the lamination step.
[0193] In [Fig.5], the solid arrows indicate the folding of the conductive tracks 150 under the flat plastic layer of the insert 170.
[0194] In this case, said insert 170 supporting the second electronic circuit is sandwiched between the two external layers 110, 120, as illustrated in [Fig.5], and the second electronic circuit comprising the set of pairs 160 of contact pads, identified by dashed dots in [Fig.5], is preferably arranged on an insert 170 separate from the insert 130 comprising the first electronic circuit forming the antenna 131.
[0195] It is appropriate to prevent the conductive tracks 150 of the second electronic circuit from, by their folding, short-circuiting the conductive tracks 133 of the first electronic circuit which form the antenna 131.
[0196] For this purpose, it is possible to provide, as illustrated in [Fig.6A], to insert an electrically insulating covering layer 190, known by the Anglicism “overlay”, between the insert 130 supporting the antenna 131 and the insert 170 supporting the second electronic circuit.
[0197] Alternatively, as illustrated in [Fig.6B], provision may be made to cover the conductive tracks 133 of the first electronic circuit which form the antenna 131 by a varnish 200, electrically insulating.
[0198] Alternatively, as illustrated in [Fig.6C], it can be provided that by construction, by drawing the tracks, the conductive tracks 133 of the insert 130 supporting the antenna 131 and the conductive tracks 150 of the insert 170 supporting the second electronic circuit are arranged so as not to overlap.
[0199] In a third variant, the card 100 comprises a metal plate 180, which is advantageously used as an electrical conductor of the second electronic circuit.
[0200] In this case, the metal plate is split into a plurality of sectors 181, electrically insulated two by two, each sector playing the role of conductive track of the second electronic circuit, and being in electrical contact individually with the microcontroller 140, by one or more electrical connections, as illustrated in [Fig.4],
[0201] The metal plate 180 also serves as an insert 170 supporting the second electronic circuit as illustrated in [Fig.4], in addition to the insert 130 supporting the antenna 131.
[0202] The metal plate 180 is configured so that two adjacent sectors 181 are spaced apart from each other by a predetermined distance, preferably less than the width of a finger, and in this case less than 1 cm, so that the physical contact of a finger on two adjacent sectors closes the corresponding switch.
[0203]
[0204] According to a second embodiment, as illustrated in [Fig.3], the pairs 160 of contact pads, represented by dashed lines, are accessible via the upper face and / or via the lower face of the card 100.
[0205] In this case, at least one of the upper face and the lower face of the card 100 comprises a set of recesses 111, each recess 111 giving access to a respective pair 160 of contact pads arranged on the insert 170 supporting the second electronic circuit.
[0206] In this case, the second electronic circuit comprising the set of pairs of contact pads can be arranged on an insert 170 separate from the insert 130 supporting the first electronic circuit forming the antenna 131, or on the same insert 130 as illustrated in [Fig.3].
[0207]
[0208] It is possible to combine the above embodiments or variants.
[0209] For example, in a manner not illustrated, it may be provided that certain pairs 160 of contact pads are formed by a cutout of the insert 170 supporting the second electronic circuit and accessible via the edge of the card 100; and that other pairs 160 contact pads are accessible from the upper face and / or the lower face of the card 100.
[0210] As illustrated in [Fig.7], it can be provided that the pairs 160 of contact pads are accessible via at least one of the upper face and lower face of the card 100, and via the edge of the card 100.
[0211] For this purpose, it is also possible to locally thicken the conductive tracks 150 to form the contact pads, as illustrated in [Fig.8].
[0212]
[0213] * Function(s) of the pairs of contact pads *
[0214] Each pair 160 of contact pads has a switch function.
[0215] These switches can be used to supply or cut off the power supply to an electronic device.
[0216] For example, with a card 100 equipped with N electronic devices, it is possible to control all or part of the N electronic devices by closing the N corresponding switches, with N a natural integer.
[0217] In one embodiment, it can be provided that a given electronic device is in electrical connection with the microcontroller 140 by several pairs of contact pads in series.
[0218] Preferably, provision is made for some switches to be default closed or inoperative, as decoys, and other switches to be default open.
[0219] In this case, knowledge of all the switches open by default is equivalent to a code, therefore to a memory factor.
[0220] Thanks to this configuration, it is possible to power said electronic device if all the switches open by default are closed.
[0221] Preferably, the total number of switches open by default is between 1 and 5, and the total number of switches is greater than 5.
[0222] Preferably, it is generally provided that the switch corresponding to each pair 160 of contact pads is open by default and closed upon physical contact between the pads of said pair and the skin of a user.
[0223]
[0224] * OPERATION *
[0225] Beyond the possible selective activation of electronic devices, the pairs 160 of contact pads can be used as an authentication factor, in this case memory.
[0226] For this purpose, it is planned to record a secret code in a memory of the card 100.
[0227] The secret code is a binary code recorded in a memory accessible to the micro controller 140, it is distinct from the possible PIN code. It includes a predefined number of bits.
[0228] Like the PIN code, the secret code can be pre-assigned to the user of the smart card 100 or predefined by the latter in an enrollment step.
[0229] The microcontroller 140 detects the closing of each switch upon physical contact between a pair 160 of contact pads with the skin of a user.
[0230] The open or closed state of each switch corresponds to a 0 / 1 bit value.
[0231] The microcontroller 140 can then calculate the code which corresponds to the open or closed state of all the switches and compare the calculated code to the recorded secret code.
[0232] The microcontroller 140 can then emit a signal which is a function of the result of the comparison.
[0233] For example, for a bank card 100, the microcontroller 140 is configured to emit a signal which is a contactless payment authorization if the calculated code is identical to the secret code.
[0234] Typically in this case, a cardholder positions his fingers on a set of pairs 160 of contact pads and places the card 100 in the field of a card reader, which electrically powers the microcontroller 140 via the antenna 131.
[0235] The microcontroller 140 reads the secret code in memory and calculates the code corresponding to the closed switches, therefore to the position of the fingers on the pairs 160 of contact pads.
[0236] If the calculated code is equal to the secret code, then the microcontroller 140 emits a contactless payment authorization signal.
[0237] In a first embodiment, the calculated code and the secret code are a combination.
[0238] Combinations are arrangements of objects that do not take into account the order in which these objects are placed. For example, code 1234 is equivalent to code 4321.
[0239] In a second embodiment, the calculated code and the secret code are an arrangement.
[0240] In this case, the order in which the objects are selected is important. For example, code 1234 is different from code 1243.
[0241] Preferably, the calculated code and the secret code are without repetition, except by implementing a timer, described below.
[0242] In a third embodiment, the card 100 further comprises a timer, in electrical connection with the microcontroller 140.
[0243] In this case, the microcontroller 140 is further configured to calculate the delay between the closing of a switch and the closing of the switch which is consecutive to it, and the calculated code and the secret code are a function of the closing delay between two consecutive switches. More precisely, the calculated code is a function of the closing delay between two consecutive switches, and the secret code is a function of the delay between two consecutive bits.
[0244] For example, the secret code is a combination of the numbers 1234. With a timer, one can provide that the secret code is a combination of the numbers 1.2..3.. .4; with "." a predetermined time value, for example 1 second, or in this case a predetermined time range, for example [0.5 second - 1 second].
[0245] In this case if the calculated code is 1.2..3...4, or 1.4..3...2, or 2.4..3...1, etc. then the microcontroller 140 considers that the calculated code is equal to the secret code because the calculated code is a combination of the secret code and the time interval between 2 consecutive bits is respected.
[0246] But if the calculated code is 1.2..3...5, then the microcontroller 140 considers that the calculated code is different from the secret code, because the values of the bits do not correspond, although the time interval between 2 consecutive bits is respected.
[0247] Similarly, if the calculated code is 1.2.3.4, then the microcontroller 140 considers that the calculated code is different from the secret code, because although the calculated code is a combination of the secret code, the time interval between 2 consecutive bits is not respected.
[0248] We thus have a double level of security, a double memory factor.
[0249] The current between the set of pairs of contact pads and the microcontroller 140 is direct current or alternating current.
[0250] The present invention is not limited to the embodiments previously described.
[0251] It can be provided that the card 100 comprises a set of markings, visual markers, each pair of contact pads 160 being marked by a respective marking, for example a geometric shape or a color.
[0252] Thanks to this feature, memorizing and "entering" the secret code can be easier.
[0253]
[0254] Nomenclature
[0255] 100 Smart card
[0256] 110 first outer layer
[0257] 111 recess of the first outer layer
[0258] 120 second outer layer
[0259] 130 insert supporting the antenna
[0260] 131 antenna
[0261] 132 micro-antenna
[0262] 133 conductive tracks of the first electronic circuit
[0263] 140 microcontroller
[0264] 150 conductive tracks of the second electronic circuit
[0265]
[0266]
[0267]
[0268]
[0269]
[0270] 160 pair of contact pads 170 insert supporting the second electronic circuit 180 metal plate 181 sector of the metal plate 190 covering layer 200 varnish
Claims
Claims
1. Smart card (100) comprising: - a first external layer (110) forming an upper face - a second external layer (120) forming a lower face, - an insert (130) comprising a first electronic circuit forming an antenna (131) for communicating with a card reader, the insert being sandwiched between the two external layers, - a secure element which is configured to be supplied with electrical energy by the antenna (131) and may comprise an individual code (PIN) in a memory, and - a microcontroller (140), Characterized in that: - the smart card (100) further comprises a second electronic circuit in electrical connection with the microcontroller (140), and distinct, independent, from the first electronic circuit;- said second electronic circuit comprising a set of pairs (160) of contact pads, accessible from the outside of the smart card (100), each pair (160) of contact pads forming a galvanic resistive button having a switch function, the switch being open by default and closed upon physical contact between the pads of said pair and the skin of a user.;
2. A smart card (100) according to claim 1, wherein the secure element comprises a microcontroller (140); and wherein: - either the microcontroller (140) and the microcontroller of the secure element are the same, - or the microcontroller (140) is distinct from the microcontroller of the secure element.
3. Smart card (100) according to any one of the preceding claims, in which the pairs (160) of contact pads are arranged on at least one of: - at least one edge of the card (100); - at least one face of the card (100).
4. Smart card (100) according to any one of the preceding claims, in which: - the second electronic circuit comprising the set of pairs (160) of contact pads is arranged on the insert (130) comprising the first electronic circuit forming the antenna (131), or
5.
6.
7. - the second electronic circuit comprising the set of pairs (160) of contact pads is arranged on an insert (170) separate from the insert (130) comprising the first electronic circuit forming the antenna (131); the pairs (160) of contact pads being formed: - by cutting the conductive tracks (150) of the insert (170) supporting the second electronic circuit; - by folding back on itself the insert (170) supporting the second electronic circuit; or - by electrical tracks (150) possibly locally widened or thickened in the form of connection pads, and accessible by a recess (111) of the first external layer (110) or of the second external layer (120) of the card (100), opening onto the insert comprising said electrical tracks of the second electronic circuit. Chip card (100) according to claim 4, in which the second electronic circuit comprising the set of pairs (160) of contact pads is arranged on an insert (170) separate from the insert (130) comprising the first electronic circuit forming the antenna (131); the card (100) further comprising a metal plate, arranged between the two external layers or on the edge of the card (100), the second electronic circuit comprising a set of pairs (160) of contact pads being machined in said metal plate. A smart card (100) according to any preceding claim, further comprising at least one of the electronic devices among: - a display device, - a sound device, - a biometric sensor, - a memory, - a battery; each electronic device being in electrical connection with the microcontroller (140) via at least one respective pair (160) of contact pads forming a galvanic resistive button having a switch function, the closing of a switch making it possible to selectively activate the corresponding device. A smart card (100) according to any preceding claim, further comprising: - a memory in which a secret code is recorded, which is a binary code accessible to the microcontroller (140), the secret code being pre-assigned to the user of the smart card (100) or predefined by the latter in an enrollment step; and in which the microcontroller (140) is configured to: * detect the closing of each switch during physical contact between a pair (160) of contact pads with the skin of a user; * calculate the code which corresponds to the open or closed state of all the switches, * compare the calculated code with the recorded secret code, and * emit a signal which is a function of the result of the comparison.
8. A smart card (100) according to any preceding claim, wherein: the microcontroller (140) is configured to be indifferent to the order of closing of the set of switches, so that the calculated code and the secret code are a combination.
9. A smart card (100) according to any one of claims 1 to 9, wherein: the microcontroller (140) is configured to determine the closing order of the set of switches, such that the calculated code and the secret code are an arrangement.
10. A smart card (100) according to any one of claims 8 to 10, further comprising: - a timer, in electrical connection with the microcontroller (140); and wherein: - the microcontroller (140) is further configured to calculate the delay between the closing of a switch and the closing of the switch which is consecutive to it; the calculated code and the secret code being a function of the closing delay between two consecutive switches.
11. A smart card (100) according to any preceding claim, wherein the current between the set of pairs of contact pads and the microcontroller (140) is a direct current or an alternating current.
12. A smart card (100) according to any preceding claim, wherein the smart card (100) is a bank card (100), wherein the microcontroller (140) is configured to issue a contactless payment authorization if the calculated code is identical to the secret code.