US Patent 11151815 Key information sharing system, delivery device and user terminal

A key information sharing system includes a delivery device that delivers key information as first information for a control device equipped in an object and a user terminal that receives the first information delivered from the delivery device. The delivery device adds second information that allows the first information to be transferred between the user terminal and a third-party terminal without the delivery device, to the first information to be delivered to the user terminal. The user terminal transmits the first information to the third-party terminal in response to an input operation by a user, when the user terminal receives the first information to which the second information has been added.