The problem is to make a reliability decision on printed matter without using special ink or a dedicated blank. At least a part of a feature of a state included in printed matter is recorded by using a predetermined method at the time of printing. At the time of verification, the feature of the state acquired from the printed matter is compared with the feature recorded at the time of printing to conduct verification. As this feature, a feature value determined on the basis of a feature of the state of the printed matter, in the state of the printed matter determined in association with spatial distribution of a coloring portion on the printing surface, at the time when printing first information to be recorded is used.