An authorization server capable of communicating with a server configured to provide a resource service to an apparatus connected via a network, and the apparatus including a resource service cooperation application using the resource service, the authorization server comprising: authentication means configured to authenticate a user based on input authentication information; authorization means (602, 603) configured to issue first authorization information (parentToken11335577, parentTokenWWXXYYZZ) in response to permission to delegate authorization of the authenticated user; reception means configured to receive a request of a request source for delegating authorization for using the resource service by the resource service cooperation application, and receive the first authorization information for accessing the resource service; issuing means configured to identify the authorization based on the first authorization information, providing at least parts of the identified authorization to the resource service cooperation application, and issuing second authorization information (childToken12345678, childTokenABCDEFGH) for identifying the given authorization; and transmission means configured to transmit the second authorization information issued by the issuing means to the request source, wherein in case at least parts of the identified authorization are given to the resource service cooperation application the issuing means is configured to determine whether the authorization requested by the request source falls within the identified authorization, and if the requested authorization is determined to fall within the identified authorization, forwarding the requested authorization to the resource service cooperation application and issuing the second authorization information (childToken12345678, childTokenABCDEFGH) for identifying the given authorization. authentication means configured to authenticate a user based on input authentication information; authorization means (602, 603) configured to issue first authorization information (parentToken11335577, parentTokenWWXXYYZZ) in response to permission to delegate authorization of the authenticated user; reception means configured to receive a request of a request source for delegating authorization for using the resource service by the resource service cooperation application, and receive the first authorization information for accessing the resource service; issuing means configured to identify the authorization based on the first authorization information, providing at least parts of the identified authorization to the resource service cooperation application, and issuing second authorization information (childToken12345678, childTokenABCDEFGH) for identifying the given authorization; and transmission means configured to transmit the second authorization information issued by the issuing means to the request source, wherein in case at least parts of the identified authorization are given to the resource service cooperation application the issuing means is configured to determine whether the authorization requested by the request source falls within the identified authorization, and if the requested authorization is determined to fall within the identified authorization, forwarding the requested authorization to the resource service cooperation application and issuing the second authorization information (childToken12345678, childTokenABCDEFGH) for identifying the given authorization.