For conventional electronic stamps, there had been a limit in the amount of electrode arrangement patterns that could be set, and the recognition accuracy of the “Capacitance Code” had been a lingering issue. Our C-Stamp is equipped with a special mechanism that can control the ON/OFF of the current flowing between a human finger and an electrode. In addition, a unique method for controlling detection/non-detection of the electrodes by a smartphone has been developed, allowing a large number of electrode arrangement patterns to be detected without any misrecognition. In addition, forging is difficult. Therefore, it is possible to identify and authenticate different stamps used in different locations in the thousands, and thus it is possible for each store to provide various services unique to the location.