Hardware Security
Which is NOT a countermeasure against fault injection attacks?
- APlacing sensors that detect voltage or clock anomalies and stopping when they trigger
- BPerforming important checks only once to speed up processing
- CComputing critical results twice or verifying them inversely, withholding output on mismatch
Show answer and explanation
Answer: B. Performing important checks only once to speed up processing
Fault injection tries to defeat protection with a single induced error, so a check performed only once becomes the weak point. Countermeasures include sensors for voltage, clock and light, redundancy that repeats critical computations or comparisons and cross-checks the results, and responses such as erasing keys when a fault is detected. Software also double-checks critical branches and uses success and failure codes that differ in many bits.
- A. This is an effective countermeasure.
- B. Correct. A single check can be skipped by a single glitch.
- C. This is an effective countermeasure.