Patent ID: 7725924

Claim:
A network system comprising: a network device configured to perform a plurality of functions; and an authentication device; wherein the authentication device includes a storing unit that stores identification information items indicating users who use the network device, and group information items indicating respective groups to which the users belong; and a transmitting unit that transmits, upon receiving from the network device an identification information item indicating one of the users trying to use the network device, a group information item indicating the group to which the user indicated by the received identification information item belongs; and the network device includes a storing unit that stores use permission information items on a per-group basis, each item indicating which of the plurality of functions of the network device is permitted to be used by a respective group, wherein the storing unit of the network device further stores a use permission information item for a default group, indicating which function is permitted to be used by the default group; a transmitting unit that transmits the identification information item indicating the user trying to use the network device to the authentication device; and a determining unit that determines which of the plurality of functions of the network device the user trying to use the network device is permitted to use, based on the group information item received from the authentication device and a respective user permission information item stored in the storing unit, wherein if the group information item received from the authentication device indicates that the user trying to use the network device belongs to none of the groups, the determining unit of the network device determines that the user is permitted to use a function permitted to be used by the default group.