Abstract: An electronic apparatus with a clock authentication function includes a first signal wire for a clock, a clock device, an electronic device, and an authentication unit. The clock device includes a clock generation unit containing circuitry configured to output a clock signal to the first signal wire and a first signal generation unit containing circuitry configured to generate a first signal synchronized with a clock signal generated by the clock generation unit. An electronic device includes an electronic circuit to which a clock signal is input via the first signal wire and a second signal generation unit containing circuitry configured to generate a second signal synchronized with a clock signal being input to the electronic circuit. The authentication unit includes circuitry configured to authenticate a clock signal being input to the electronic circuit based on whether or not the first signal and the second signal are synchronized with each other.