| 摘要 |
The invention prevents unauthorized use of data in communications. When terminals with different data transmission rates are simultaneously connected to a host computer, the host computer sets a single common data communication rate to all the terminals to assure synchronization. The host computer is connected each terminal via communications network. The host computer sends a data body to each terminal over a unilateral communications link in a cyclic manner while a bilateral communications link is established between the host computer and each terminal. Response to an individual request from each terminal, the host computer downloads descrambling data for descrambling and a loader for executing the data body. The host computer determines from among the terminals, any terminal having a communications means that sets the lowest data transmission rate, and sets the data transmission rates of the terminals simultaneously connected thereto to the lowest rate.
|
