High Security Television Transmission using Digital Processing

The availability of low-cost TV Receive Only (TVRO) satellite earth stations has made video / audio tele-conferencing an affordable alternative. Unfortunately, the same economic considerations have created a security problem due to unauthorized "eavesdropping". A need exists to scramble these television signals in order to establish a secure communications network. Along with hard security for both video and audio, the installation of a scrambling system offers additional benefits. These include multiple high quality audio channels, ASCII data channel and addressability based on each individual descrambler. The paper compares analog and digital methods of scrambling with respect to encryption technology and signal degradation.