Data transmission system using USB interface

摘要

A data transmission system using a USB interface is provided. The system includes a terminal, a data transmission cable, and an electronic signature key. One end of the data transmission cable is a first USB interface, and the other end is an interface applied to connect to the terminal, and transmits information transmitted from the terminal directly to the electronic signature key. The electronic signature key includes a second USB interface, a security chip, and a gate circuit. The second USB interface is connected to the first USB interface in the data transmission cable and receives information transmitted from the terminal. The security chip is connected to the second USB interface and detects the information received by the second USB interface. Further, according to the information, a type of a data transmission protocol to be used is determined, control information is generated according to the type of the data transmission protocol, and a demodulation method that matches the type of the data transmission protocol is used. The received information is demodulated to obtain demodulated data. The gate circuit is connected to the second USB interface and the security chip, and receives control information transmitted from a control terminal in the security chip. Further, the modem terminal applied to the data transmission protocol is turned on in the second USB interface and the security chip according to the control information. [Selection] Figure 1