Method For Protecting A Payment Terminal

A method for protecting a payment terminal, said payment terminal comprising:

• a data encryption key accessed for the encryption of data to be secured;
• a module for monitoring at least one physical parameter of the terminal comprising a means for measuring said physical parameter;
• a microcontroller;
• a counter unit of the microcontroller,
• a clock, the counter unit being slaved to said clock to increment at regular intervals a counter value of the counter unit;
• said method comprising the following steps:
• measuring a physical parameter by the measuring means of the monitoring device;
• comparing the measured value with a predetermined threshold value, corresponding to a physical attack of said terminal by the monitoring device;
• deleting the access to the data encryption key by the microprocessor if one of the following conditions is met:
• at least one physical parameter value signifies a physical attack of said terminal;
• the counter value is greater than a predefined threshold value;
• reinitializing the counter unit by the monitoring device;
• and
• wherein the measuring, comparing, and reinitializing steps are executed periodically.