Provided are a semiconductor evaluation element capable of analytically estimating the amount of DC variation of a MOS transistor which is caused by formed contacts, and an evaluation circuit and an evaluation method using the semiconductor evaluation element. Thus, the region of a predetermined object in the video can be described with a small quantity of data. The verification key includes a public verification key. The display device receives the video signals from the camera device when the corresponding vehicle is in proximity to the camera device and presents the video signals as a video image of the dangerous location to a driver of the vehicle. More than one party can cooperate in adding distinguished watermarks at various stages of distribution without destroying watermarks previously placed in the content.