A switching device for controlling a connection between a private computer, a shared computer, and a terminal, including: a connecting unit that connects each terminal to a corresponding private computer in a default status, and switches a connection destination of the terminal to a private computer corresponding to the terminal or the shared computer when a connection switching request transmitted from the terminal has been received; and a security unit that executes for each terminal, identification processing on the data that has been received from any one terminal and output to the at least one private computer or the shared computer.