The vibration in the power supply voltage will cause the shifting of transistor electrical level value which can be used for Extract MCU Power Glitches. The result is the triggers in it can sample their input in different times when we try to crack MCU, or extract the wrong security fuse state.

Normally the instantaneous power supply voltage increase or decrease will generate noise, so generally within 10 cycles of MCU extract, power supply noise will be applied on the program interfaces of MCU which can affect the processor operation or the hardware security circuit. Weak point can be more difficult to use than time noise. Since for time zone parameters, vibration, up/down time length are all variables.

A example is extract MCU MC68C05B6, if the power supply voltage decrease to 50-70% when operate the instruction. The processor can extract the value FFh from the EEPROM instead of the real value. This can refers to the security fuse unencrypted state.

The trick is calculate the operation time carefully to decrease the voltage, otherwise the processor will go into the pause situations or reset states. This kind of extract mcu embedded firmware task is not difficult, target order will be operated after reset within the first 100 cycles. MCU extracter can use vector generator to build a noise source of his own.