Device for securing a capacitive keypad and corresponding terminal
A securing device is provided for securing a capacitive keypad of an electronic payment terminal having at least one processor for managing keys of the capacitive keypad. The securing device is configured for communicating with the processor and includes a driving module for driving at least one simulation element for simulating at least one keystroke on the capacitive keypad. The driving module includes a receiver for receiving at least one simulation command randomly transmitted by the processor.
1. A securing device for securing a capacitive keypad of an electronic payment terminal comprising at least one processor for managing keys of said capacitive keypad, wherein:
said securing device is configured to communicate with said processor,
said securing device comprises a driving module configured to drive at least one simulation element configured to simulate at least one keystroke on said capacitive keypad,
said driving module comprises a receiver configured to receive at least one simulation command randomly transmitted by said processor,
said simulation element implements at least one capacitor of a predetermined value called a parasitic capacitor,
said driving module activates this parasitic capacitor by closing at least one switch, said parasitic capacitor being connected, when said switch is closed, to at least one receiver electrode connected to at least one key of said capacitive keypad, and
said driving module is configured to drive at least two parasitic capacitors upon reception of at least two distinct simulation commands coming from said processor, each of said parasitic capacitors being connected to a distinct receiver electrode enabling simulation of at least all the numerical keys of said capacitive keypad.
2. The securing device according to claim 1 , wherein said switch is a transistor.
3. The securing device according to claim 1 , wherein said predetermined value of said parasitic capacitor corresponds appreciably to a capacitive value representing a stroke on a key of said capacitive keypad.
4. The securing device according to claim 3 , wherein the securing device is implemented in a secure zone of said electronic payment terminal.
5. An electronic payment terminal comprising the securing device according to claim 1 .
6. A method comprising:
securing a capacitive keypad of an electronic payment terminal comprising at least one processor for managing keys of said capacitive keypad, wherein securing comprises:
receiving by a securing device, configured to communicate with said processor and comprising a driving module configured to drive at least one simulation element configured to simulate at least one keystroke on said capacitive keypad, at least one simulation command transmitted randomly by said processor;
in response to receiving the at least one simulation command, driving at least one simulation element by said securing device enabling simulation of at least all keystrokes on said capacitive keypad, said simulation element implementing at least one capacitor of a predetermined value called a parasitic capacitor, wherein driving at least one simulation element comprises:
activating, by said driving module of said securing device, the parasitic capacitor by closing at least one switch, said parasitic capacitor being connected, when said switch is closed, to at least one receiver electrode connected to at least one key of said capacitive keypad, wherein said driving module of said securing device drives at least two parasitic capacitors upon reception of at least two distinct simulation commands coming from said processor, each of said parasitic capacitors being connected to a distinct receiver electrode enabling simulation of at least all the numerical keys of said capacitive keypad.
7. A non-transitory computer-readable medium comprising a computer program stored thereon, which is executable by a processor of a securing device and comprises program code instructions to execute a method of securing when the program is executed by the processor, wherein the method comprises:
securing a capacitive keypad of an electronic payment terminal comprising at least one processor for managing keys of said capacitive keypad, wherein securing comprises:
receiving by a securing device, configured to communicate with said processor and comprising a driving module configured to drive at least one simulation element configured to simulate at least one keystroke on said capacitive keypad, at least one simulation command transmitted randomly by said processor;
in response to receiving the at least one simulation command, driving at least one simulation element by said securing device enabling simulation of at least all keystrokes on said capacitive keypad, said simulation element implementing at least one capacitor of a predetermined value called a parasitic capacitor, wherein driving at least one simulation element comprises:
activating, by said driving module of said securing device, the parasitic capacitor by closing at least one switch, said parasitic capacitor being connected, when said switch is closed, to at least one receiver electrode connected to at least one key of said capacitive keypad, wherein said driving module of said securing device drives at least two parasitic capacitors upon reception of at least two distinct simulation commands coming from said processor, each of said parasitic capacitors being connected to a distinct receiver electrode enabling simulation of at least all the numerical keys of said capacitive keypad.