1. A program editing method for editing a program written in an object oriented programming language that satisfies two conditions, a condition according to which a program includes the concept of a package that admits mutual data by referring only to a specific visibility that is designated, and a condition according to which a program includes an access control system for obtaining an access authority based on principal information provided to specify the references of an access requester, said program editing method comprising: a package name replacement step of replacing package names allocated for a plurality of classes that constitute an application program having a single package name; a data attribute change step of changing an attribute of internal fields of said classes that are not referred to by a source outside said application program, so as to accept an access request for a reference from the same package; and an access authority provision step of providing an access authority that is based on said principal information for said application program that has been processed at said package name replacement step and said data attribute change step.