Command authentication process between a master and a slave station encrypted messages

摘要

A slave station (12), such as an orbiting satellite, and a master station (16), such as a ground control station, have their own lists of identical random pads (80,78). When the master station sends a critical command to the slave station, a selected one of the pads (86) is combined with the command and transmitted to the slave station as a data communication message (89). Each pad is used only once. The slave station evaluates the received pad value using its version of the same selected pad. If the evaluation detects correspondence, then the command is authenticated and the slave station acts upon the command. The random pads are generated (154) by the slave station. They are encrypted (160) using an asymmetric encryption process and transmitted (166) to the master station so that the master and slave stations will operate on common sets of pads.