What do the lights at the end of the hardware key indicate?

For keys with a single light, the light indicates that the key and the software are communicating. If this light is off, it indicates a problem with the key or the hardware driver.

For keys with two lights, the red light indicates that the computer sees the key. If the light is off, it indicates a problem with the key or the hardware driver. The blue light, when flashing, indicates that data is being sent between the computer and the key.