Study on the effect of clock rise time on fault occurrence under IEMI

A method of the fault injection to a cryptographic equipment injects intentional electromagnetic interference (IEMI) on its power line. An IEMI fault is caused when the injection is superimposed on the rising portion of the clock signal, and the vulnerability increases if the clock pulse has long rise time. If the rise time is short, the clock signal has widely spread frequency spectrum, and may cause electromagnetic disturbance. The clock rise time should be considered as trade-off between resistance against fault injection and electromagnetic compatibility (EMC). An experimental study showed how clock rise time effects on occurrence of fault injection, and distribution of high frequency components of the clock signal was observed.