An information processing method is an information processing method executed by an information processing device in a control network system that includes: a plurality of electronic control units each capable of executing a service that includes execution of predetermined processing and capable of mutual access regarding services; and a plurality of edge access permission devices each determining whether to permit or deny the access based on a predetermined access policy. The information processing method includes: obtaining, from the plurality of edge access permission devices, policy verification results, each including a determination result indicating whether the access is permitted or denied; and outputting verification information related to a master policy verification result that includes a final determination result indicating whether the access is permitted or denied, based on the policy verification results from the plurality of edge access permission devices.