Secure sca broadcasting system including subscriber actuated portable receiving terminals

Abstract From the Canadian patent

A secure information broadcasting system including a central transmitting station for encoding data in binary form utilizing a keyword and transmitting a FM-SCA signal phase shift modulated by the encoded data. Each of a plurality of portable receiving terminals has an identification number stored therein. When a subscriber desires to display the broadcast information on his terminal, he enters a unique password which combined with the identification number to generate the keyword. The keyword is utilized to decode the received binary data. The portable terminal includes a receiver for decoding the phase shifted FM-SCA signal into the encoded binary data; a keyboard for entering the …