An authentication system comprising: an authentication server; a terminal device configured to be connected to said authentication server and be authenticated by said authentication server; a peripheral device configured to be connected to said terminal device; and a personal group management server configured to be connected to said terminal device, wherein said peripheral device is configured to transmit a peripheral device name which is a name of said peripheral device itself and a peripheral device address which is an address of said peripheral device itself as a peripheral device identifying data for identifying said peripheral device itself to said terminal device when said peripheral device accesses to said terminal device, said terminal device is configured to authorize said peripheral device on the basis of said peripheral device identifying data, to generate authentication data of said peripheral device by using said peripheral device name and said peripheral device address of said peripheral device upon determining that said peripheral device is authorized, to relate said peripheral device with said authentication data with a peripheral device ID for identifying said peripheral device and to transmit said authentication data, said peripheral device address and said peripheral device ID to said authentication server and to said peripheral device, said authentication server is configured to perform a first authentication with respect to said peripheral device by using said authentication data, and to notify said authenticated peripheral device of a personal group management server address which is an address of said personal group management server, said peripheral device is configured to transmit said peripheral device identifying data for identifying said peripheral device and terminal device identifying data for identifying said terminal device to said personal group management server on the basis of said personal group management server address, and said personal group management server is configured to generate a personal group list by relating said peripheral device identifying data to said terminal device identifying data, and to transmit said personal group list to said terminal device, said peripheral device is configured to transmit said authentication data and said peripheral device ID to said authentication server for a second authentication; and said authentication server is configured to execute said second authentication by comparing said authentication data and said peripheral device ID received from said terminal device with said authentication data received from said peripheral device on the basis of said peripheral device ID. an authentication server; a terminal device configured to be connected to said authentication server and be authenticated by said authentication server; a peripheral device configured to be connected to said terminal device; and a personal group management server configured to be connected to said terminal device, wherein said peripheral device is configured to transmit a peripheral device name which is a name of said peripheral device itself and a peripheral device address which is an address of said peripheral device itself as a peripheral device identifying data for identifying said peripheral device itself to said terminal device when said peripheral device accesses to said terminal device, said terminal device is configured to authorize said peripheral device on the basis of said peripheral device identifying data, to generate authentication data of said peripheral device by using said peripheral device name and said peripheral device address of said peripheral device upon determining that said peripheral device is authorized, to relate said peripheral device with said authentication data with a peripheral device ID for identifying said peripheral device and to transmit said authentication data, said peripheral device address and said peripheral device ID to said authentication server and to said peripheral device, said authentication server is configured to perform a first authentication with respect to said peripheral device by using said authentication data, and to notify said authenticated peripheral device of a personal group management server address which is an address of said personal group management server, said peripheral device is configured to transmit said peripheral device identifying data for identifying said peripheral device and terminal device identifying data for identifying said terminal device to said personal group management server on the basis of said personal group management server address, and said personal group management server is configured to generate a personal group list by relating said peripheral device identifying data to said terminal device identifying data, and to transmit said personal group list to said terminal device, said peripheral device is configured to transmit said authentication data and said peripheral device ID to said authentication server for a second authentication; and said authentication server is configured to execute said second authentication by comparing said authentication data and said peripheral device ID received from said terminal device with said authentication data received from said peripheral device on the basis of said peripheral device ID.