A system for securely providing restricted display information having an encoder-transmitter for transmitting selected update data using information identification codes as enabling reception keys and a plurality of uniquely identified decoder-receivers for receiving the update data for display on a video screen. Authorized decoders are provided with enable reception keys so that subsequently transmitted data having an information identification code matching a reception key at a decoder-receiver may be received for subsequent display on the video screen. Symbolic signaling is used so that enabling a decoder-receiver with a reception key also provides display coordinate information for displaying the update data in the proper relative display location for the video screen of that enabled decoder, so that the update data subsequently transmitted is displayed using that display coordinate information. Tile messaging and cellular micrographic transmission techniques are used to reduce the volume of data transmitted to changed display information (update data), wherein cells of characters are transmitted as one byte of data and cells of pixel data are transmitted a plurality of bytes of data. Each decoder-receiver may have a plurality of video screens separately and uniquely identified such that encoded update data and other messages are transmitted for specific video screens. The system includes multiplexing display information and television signals from different sources and transmitting the multiplexed signals to the decoder-receivers for selectively displaying different combinations of display information and/or television signals on different video screens.