A data processing method is performed by an edge device acquiring collected data from a collection target and a first computer capable of communicating with the edge device. The method includes: a first calculation process of, by the edge device, storing the collected data in a secure region to which referring of internally stored information from outside is not allowable and calculating first data which has a data amount less than the collected data and is irreversible in the secure region based on the stored collected data; a first communication process of, by the edge device, transmitting the first data calculated through the first calculation process to the first computer; and a second calculation process of, by the first computer, calculating second data based on the first data transmitted from the edge device through the first communication process.