AUTHENTICATION METHOD USING HOLOGRAM BODY AND AUTHENTICATION DEVICE USING HOLOGRAM BODY, AND HOLOGRAM BODY TO BE USED IN AUTHENTICATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an authentication method that can further surely prevent a hologram body from being reused.SOLUTION: A hologram body 10 has: a hologram layer 11; and a thermosensitive coloring layer 12 that develops coloring by application of heat. An authentication method comprises the processes of: irradiating toward an incident surface of the hologram body 10 attached to an adhered body 20 with light; and determining whether intensity of light diffracted by the hologram body 10 exceeds a predetermined threshold. The threshold is set so as to be smaller than intensity of light diffracted by the hologram body of a state where the thermosensitive coloring layer 12 does not develop coloring, and is set so as to be larger than intensity of light diffracted by the hologram 10 of a state where the thermosensitive layer 12 develops the coloring.