Event counter in a system adapted to the JavaCard language
AssigneeProton World International N.V.
InventorOlivier Van Nieuwenhuyze
Life of this patent
Estimating the term…
Abstract
The implementation of a counter in a microcontroller adapted to the JavaCard language while respecting the atomicity of a modification of the value of this counter, wherein the counter is reset by the sending to the microcontroller of an instruction to verify a user code by submitting a correct code, and the value of the counter is decremented by the sending to the microcontroller of the instruction to verify the user code with an erroneous code value.
Claims18
A method for implementing and using a counter to monitor execution of at least a portion of a JavaCard program in a microcontroller adapted to the JavaCard language, the method comprising:
- accessing a correct code value and an erroneous code value stored in a non-volatile memory of the microcontroller;
- and
- each time the at least a portion of the JavaCard program being monitored is executed, issuing a user code verification instruction with the erroneous code value included as a parameter of the user code verification instruction, the user code verification instruction being configured to cause the microcontroller to:
- compare the parameter of the user code verification instruction with the correct code value stored in the non-volatile memory, and
- decrement a value of the counter in response to the parameter not being the correct code value.
A device comprising:
- a microcontroller adapted to the JavaCard language and configured to implement a counter to monitor execution of at least a portion of a JavaCard program by:
- accessing a correct code value and an erroneous code value stored in a non-volatile memory of the microcontroller;
- and
- each time the at least a portion of the JavaCard program being monitored is executed, executing a user code verification instruction with the erroneous code value included as a parameter of the user code verification instruction, the user code verification instruction being configured to cause the microcontroller to:
- compare the parameter of the user code verification instruction with the correct code value stored in the non-volatile memory, and
- decrement a value of the counter in response to the parameter not being the correct code value.
A system comprising:
- a microcontroller adapted to the JavaCard language and configured to implement a counter to monitor execution of at least a portion of a JavaCard program by:
- accessing a correct code value and an erroneous code value stored in a non-volatile memory of the microcontroller;
- and
- each time the at least a portion of the JavaCard program being monitored is executed, executing a user code verification instruction with the erroneous code value included as a parameter of the user code verification instruction, the user code verification instruction being configured to cause the microcontroller to:
- compare the parameter of the user code verification instruction with the correct code value stored in the non-volatile memory, and
- decrement a value of the counter in response to the parameter not being the correct code value.
Dependencies are inferred from the claim text.