An image forming apparatus using a service of a server apparatus decrypts encrypted common authentication information of the image forming apparatus based on secret key information for decrypting the common authentication information, and then requests encrypted individual authentication information of the image forming apparatus from the server apparatus based on decrypted common authentication information and identification information for identifying the image forming apparatus. The image forming apparatus obtains the individual authentication information from the server apparatus, requests the server apparatus for use permission information of the service based on the decrypted individual authentication information and on service use information, and obtains the use permission information from the server apparatus.