When having established communication with a data processing apparatus, a first apparatus determines whether or not to generate authentication information based on identification information about the data processing apparatus. If it is determined that generation of authentication information is necessary, then the first apparatus generates authentication information and saves it in a memory. If it is determined that generation of authentication information is necessary, the first apparatus sends the generated authentication information to the data processing apparatus with which communication has been established. If it is determined that generation of authentication information is unnecessary, then the first apparatus sends authentication information saved in the memory to the data processing apparatus with which communication has been established. Thereby, authentication between data processing apparatuses is performed with the use of the authentication information sent from the first apparatus.