Bank card with display screen

Bank cards have chips to secure the transaction. The EMV standard was created by Europay, MasterCard and Visa whose initials are the standard for defining a standard for interoperability and security between card bank smart. For a card is EMV certified, it must be that it has a chip itself certified that features a touch interface according to ISO7816 standard and / or contactless according to ISO14443 standard. To reduce the risk of piracy, EMV chips do not have another communication interface.

Furthermore, it is also known to make smart cards with a screen and one or more pushbuttons for communicating with the card holder. These cards are little used at present and are used to generate and display a single use password for transactions by computer. Such cards typically include a chip provided with a smart card communication interface or without contact and a communication port for communicating with other integrated circuits such as for example a communication interface 12C or of ports of entry / exit programmable general purpose (GPIO). It is possible to map a microcontroller chip to communicate with a display controller which controls a liquid crystal display or a display in said "electronic ink".

One idea would be to make a credit card with a screen to display the latest transactions. A problem then arises if one wishes to carry a smart card EMV. These chips have no inlet / additional output for this type of application and for safety reasons it is preferred not to add other input / output ports.

It is therefore not possible to drive the display from an EMV chip. A solution is needed to view recent transactions performed on a smart card.

The invention is a solution to the problem. To enable the display of recent transactions, a second microcontroller is added on the smart card to perform a function interception and storage of transaction information.

More particularly, the invention is a smart card for secure transaction comprising at least one secure chip provided with a communication interface for communicating with a card reader to perform a transaction, characterized in that the card comprises Furthermore an electronic display, a battery pack, an interception circuit connected to the communication interface of the secure chip to intercept at least one type of control and storing at least one information so it can be displayed on the display .

Preferably, the interception system stores information exchanged in clear between the secure chip and the card reader. The information can be intercepted in the amount of transaction.

According to various embodiments, the card includes an actuator to allow a wearer of said card to display the intercepted information. The actuator may be a motion sensor. The actuator may be a push button used to initiate the powering of the display and the interception circuit using the battery pack and wherein a timer cuts power. The card can also include a sensor for use for inhibiting or permitting operation of the interception circuit. The use sensor is for example a light sensor.

According to various implementation alternatives, the communication interface can be a contact interface and wherein the interception circuit is connected in parallel with the contacts of the card, and / or may be a contactless interface with of a first antenna having the shape of coils within the map and wherein the interception circuit has a second antenna having the shape of coils within the card, the first and the second antenna sharing a common electromagnetic flow. If the secure chip has two communication interfaces then the interception circuit is connected to both interfaces.

The invention will be better understood and other features and advantages will become apparent from reading the description which follows, the description referring to the accompanying drawings in which the <figref idrefs="f0001 f0002">Figures 1 to 3</figref> show three embodiments of the invention.

The <figref idrefs="f0001">figure 1</figref> shows a block diagram of a first embodiment of the invention. In this embodiment, the bank card 100 is a card contact chip that comprises a secure chip 101 provided with a communication interface conforming to ISO 7816 standard and connected to a connector 102 having contact pads also defined by the 7816 standard the secure chip 101 is a chip for example meeting the EMV standard and has restricted access to data and other data called public. The restricted access data require the use of password or encrypted messages word while public data can be accessed for reading and / or writing by any reader complies with the ISO7816 standard.

When paying using the secure chip 101, the bank card 100 is inserted into a secure drive that performs verification of a PIN code entered by the cardholder to verify that the holder of the card is good, then comes the secure exchange of information via encrypted messages between the card reader and possibly a remote server to see if the debit card is authorized or not. When the transaction is complete, information is updated in the card and the reader to indicate the amount of the transaction and possibly the remaining balance of the card. The complete transaction amounts that are stored in the card with no legal value and is not carrying confidential information, they are usually stored in an unsecure memory area and therefore accessible by any type reader complies with the ISO7816 standard. These data are not sensitive data are exchanged in the clear with identifiable write commands.

To achieve the display of recent transactions, the bank card 100 is equipped with an electronic display 103, a 104 and a batch intercept circuit Battery 150. The interception circuit 150 can be achieved in a single integrated circuit or may comprise several circuits. In terms of manufacturing, the intercept circuit 150 can be produced on a substrate in the card body by lamination according to a known method which has contact with the rear face of the contact areas of the connector 102, using a known technique.

The electronic display 103 may be of the liquid crystal type or electronic ink using microbeads. The important thing is that this display 103 is fine enough to be embedded in a smart card and must also be energy efficient. The battery 104 is a ultra-thin battery integrated in a smart card. Depending on the desired service life of the card and the consumption by the pickup circuit 150 and the display 103, one can choose a rechargeable or non-rechargeable.

The interception circuit 150 includes microcontroller 151 constituting the intelligence of the device and with the programs necessary for the operation of all, a control circuit 152 for controlling the electronic display 103, a power controller 155, and a button 156 push.

The microcontroller 151 is the overall control element interception circuit. The control circuit 152 serves to transform a number to be written provided by the microcontroller 151 into electrical electronic display control signals 103. The power supply regulator 155 is used to convert the voltage supplied by the battery supply voltage to the display 103 and the circuit the interception system 150. the power controller 155 may also serve as battery charger when the battery 104 is rechargeable type. The battery recharging is performed when the card is connected to an external drive for a transaction.

The microcontroller 151 is connected to the contact areas of the connector 102 to read all the messages exchanged between the secure chip 101 and a card reader. During a transaction between the card 100 and a reader, for example terminal type of payment, the microcontroller receives all control trade and all the data that the connector 102. When the microcontroller 151 detects a command that corresponds to the entry of the amount of the transaction in the secure chip 101, the microcontroller 151 stores in non-volatile this information.

The pushbutton 156 is an actuator accessible by the card holder to trigger the display of recent transactions. Following action on the push button 156, the microcontroller 151 will awaken the interception circuit. The microcontroller 151 then reads out the last transaction he has memorized and will send a command sequence control circuit 152 to display the amount on the display 103.

A new press on the push button 156 may cause the reading and display of the previous transaction that has been stored. A long press can stop reading the transactions and switch to standby mode where the power of the secure chip 101, the display 103, the interface 153 and the drive circuit is cut and where only the supply of the microcontroller 151 is provided for the portion for the alarm via a new action on the push button. The lack of support on the pushbutton 156 for a long predetermined time, for example 1 to 2 minutes may also cause the development of the system before.

Alternatively, to save battery to the maximum, using the push button can initiate power elements of the card by the contact established by the push button to initiate an electronic switch. The advantage of such a system is that one can use a timer, for example, one to two minutes to defuse the electronic switch and shut off power completely in the card.

The <figref idrefs="f0001">2</figref> shows a block diagram of a second embodiment of the invention. For the sake of simplification of description, the common elements between the first and second embodiment have the same references and will not be further described. Also the equivalent elements will reference also referring to the first embodiment by the addition of a "b".

In this second embodiment, 100b credit card is a contactless chip card which comprises a secure chip 101 b provided with a communication interface conforming to ISO 14443 and 105 connected to an antenna consisting of turns placed in inside the card body. The secure chip 101 b is for example a chip meeting the EMV standard and has restricted access data and other so-called public data. The restricted access data require the use of passwords or encrypted messages while public data can be accessed for reading and / or writing by any player conforms to the ISO14443 standard.

When paying using the secure chip 101b, 100b bank card is placed in front of the antenna of a secure reader, secure information exchange via encrypted messages between the card reader and possibly a remote server carried out to check if the debit card is authorized or not. When the transaction is complete, information is updated in the card and the reader to indicate the amount of the transaction and possibly the remaining balance of the card. The complete transaction amounts that are stored in the card with no legal value and is not carrying confidential information, they are usually stored in an unsecure memory area and therefore accessible by any type reader according to standard IS014443. In addition the command that indicates the writing of the amount of the transaction is also sent in the clear.

To achieve the display of past transactions, 100b bank card has an electronic display 103, a battery 104 and 150b of an interception circuit. The interception circuit 150b differs from the first embodiment by using a communication interface 157 complies with the ISO 14443 standard and connected to an antenna 158. The antenna 158 is an antenna composed of a plurality of turns and also placed inside the card body. Antennas 105 and 158 are made to share a common electromagnetic flow so that the antenna receives all data received and sent by the secure chip 101 b. These two antennas are further configured so as not to interfere when they share the electromagnetic flux located outside of a card reader.

The interface 157 also allows recovery of energy from an external drive to enable charging the battery 104 through the power regulator 155. When the interface 157 detects an external field created by a card reader the interface 157 indicates to the microcontroller 151 that awakens the 150b interception circuit. The microcontroller 151 is programmed to listen for data exchange but is not configured to automatically report on detection of the field. A transaction can therefore be made between the secure chip 101 b and the card reader without the interception 150b circuit from disturbing the exchange of information. When the microcontroller 151 detects a command that corresponds to the entry of the amount of the transaction in the secure chip 101 b, the microcontroller 151 stores in non-volatile this information.

At a subsequent press of the push button 156, the transaction information is then displayed as shown in connection with the <figref idrefs="f0001">figure 1</figref>.

The <figref idrefs="f0002">3</figref> shows a block diagram of a third embodiment of the invention further incorporates the improvements that can also be used in combination with one of the previously described embodiments. For the sake of simplification of description, the common elements between the first, second and third embodiment have the same references and will not be further described. Also the equivalent elements will also reference a reference to the other embodiments by the addition of a "c".

In this third embodiment, the credit card 100c is a mixed chip card having a secure chip 101c provided with a communication interface conforming to ISO 7816 which connected to a connector 102 having contact pads also defined by the 7816 and also provided with a communication interface conforming to ISO 14443 and 105 connected to an antenna consisting of turns placed inside the card body. The secure chip 101c is such a chip meeting the EMV standard and has restricted access data and other so-called public data. The restricted access data require the use of passwords or encrypted messages while public data can be accessed for reading and / or writing by any reader complies with ISO7816 and comply with the ISO14443 standard. Whatever the used communication, wired or wireless, transaction data is sent via the write command in the clear, that is to say not encrypted.

To achieve the display of recent transactions, the 100c bank card has an electronic display 103, a battery 104 and an interception 150c circuit. The interception circuit 150c differs from the two previous embodiments by the simultaneous use of a connection of microcontroller 151 to the contact pads of the connector 102, and a communication interface 157 complies with the ISO 14443 standard and connected to an antenna 158.

Among other changes, the push button 156 is replaced by an accelerometer 170 to avoid wear problems and bad contacts of using the pushbuttons that are particularly sensitive on smart cards. Thus a gesture allows to tension the interception circuit and the display to display a transaction. It is possible to use movement signatures to be able to distinguish if you want to see a particular type of transaction, such as for example the previous or next.

Also, the use of a push button or even an accelerometer can trigger supply of the interception circuit 150c and the display 103 while the card is in the reader or in a pocket. This type of trigger can cause premature battery discharge. To address this premature discharge of the battery, using a light sensor 180 coupled with the microcontroller 151 inhibits operation if the sensor does not capture sufficient light.