Counterfeit note detection or security authentication ink and detection authentication manner

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting false bank notes with a small amount of an ink which can be readily obtained from readily available chemicals by using easy-to-handle and inexpensive tools through prompt and simple operations with high certainty in no need of expensive and large-sized apparatus and complicated operations, in addition, a method for certifying sheets of security paper and the ink therefor. SOLUTION: A bank note or a sheet of security paper is spotted with this ink and the color change at the spotted part is observed after a desired time. In the case of a false bank note, the color tone changes dark from the original color at the ink-spotted site to dark brown to gray purple; on the other hand, in the genuine bank note, no change in the color is observed where the starch included false bank notes is detected with the ink including iodine.