Countermeasure against fault injection attacks

A method, comprising:

• obtaining a first value and a second value both associated with access to a computer resource;
• performing a first comparison of the first value with the second value;
• and
• based on the first comparison indicating that the first value matches the second value,
• performing a second comparison of the first value with the second value;
• and
• based on the second comparison indicating whether or not the first value matches the second value, determining whether to generate a signal to trigger a first interrupt service routine (ISR) or a second ISR.

A system, comprising:

• a comparator circuit configured to:
• obtain a first value and a second value both associated with access to a computer resource;
• perform a first comparison of the first value with the second value;
• and
• based on the first comparison indicating that the first value matches the second value,
• perform a second comparison of the first value with the second value;
• and
• based on the second comparison indicating whether or not the first value matches the second value, determine whether to trigger a first interrupt service routine (ISR) or a second ISR.