Authentication device and authentication method

An authentication device comprising:

• an authentication unit configured to authenticate a regular user who is authorized to use a specified component;
• an information acquisition unit configured to acquire surrounding information around the specified component;
• a companion identifying unit configured to determine whether the regular user is accompanied by a companion based on successful authentication of the regular user by the authentication unit;
• a companion information identifying unit configured to identify companion information from the surrounding information acquired by the information acquisition unit based on the companion identifying unit having determined that the regular user is accompanied by the companion;
• and
• an authorization unit configured to authorize the companion to use the specified component based on the companion information identified by the companion information identifying unit, wherein
• the authentication unit is further configured to authenticate the companion who has been authorized by the authorization unit.