High-quality bis-H-tetrazol-5-yl)amine and a method for easily, safely, and inexpensively producing the compound are provided. The plurality of codes may be binary codes having possible logical values of \u22121 and +1 and may comprise an even number of codes. In specific, the amount of light emission in the still image portion is made as small as possible in a corresponding divided region of the backlight, and the amount of light emission in the moving image portion is controlled so as not to be changed as much as possible in a corresponding divided region of the backlight. Using a public key cryptosystem, the signature is provided to a certification server.