This key information generation system generates key information necessary when using a shared device and imparts this key information to a mobile terminal. Authentication is performed between a mobile terminal which has imported key information, and an authentication device provided to the device, and if said authentication is successful, the mobile terminal enables operation of the device via the authentication device. The key information generation system includes: an information management unit which manages, by associating with one another, individual information for the authentication device, a key information generating code, and usage information pertaining to the use of the authentication device; and a key information generation unit which specifies a key information generation code from the individual information and usage information managed by being associated with one another by the information management unit, and generates key information on the basis of the key information generation code.