A data process apparatus includes a management unit that receives a creation request for creating a sharable data storage space from an unauthenticated data terminal and transmit a response to the unauthenticated data terminal, an authentication unit that authenticates the access data when the data process apparatus receives an access request including a designation of the access data for accessing the shared data storage space from an unauthenticated data terminal connected to a same network as the data process apparatus, a request processing unit that receives the access request from the unauthenticated data terminal when the authentication of the access data succeeds and perform a predetermined process in accordance with the access request. The response includes access data indicating authorization for accessing the sharable data storage space and data indicating the sharable data storage created in association with the access data.