Bank ATM machines are generally metal numeric keypads, which have the advantage of preventing leakage. If it is a normal keyboard, when you press your password with your finger, the temperature of the keyboard will be changed if we use thermal sensing after the transaction has just succeeded. When the camera takes a photo, you can get a password by looking at the photo. The advantage of the metal keyboard is that the conductivity of the metal is high and the temperature changes very quickly. Even if someone photographs the picture with a thermal sensor camera, it is difficult to observe the color judgment sequence.