However, if there is no discomfort immediately after it is painted on the signboard, there is no problem..... Immediately after the signboard was made, it was shining brightly. However, it changes color after only a few years. How can it be proven that a verification task is valid? The sign maker stares at the faded part of the sign ? something verifying valid another authority No matter how beautiful and cool a billboard is, it will expose its sloppy appearance after a few years. The owner of the signboard wants to repair the worn-out signboard. It’s not unnatural for owners to decide that they want to repaint a part instead of updating the whole thing. Then, one day, suddenly a troublesome task comes to the signboard shop in the town: I want you to make a part of that signboard brighter. How can it be proven that a verification task is valid? The task of verifying something is relatively easy. Because it’s just about verifying somethin...