High Quality Content by WIKIPEDIA articles! Television encryption, often referred to as "scrambling", is encryption used to control access to pay television services, usually cable or satellite television services. The early cable based Pay-TV networks used no security. This led to problems with people connecting to the network without bothering to pay. Consequently, some methods were developed to frustrate these self-connectors. The early Pay-TV systems for cable television were based on a number of simple measures. The most common of these was a channel based filter that would effectively stop the channel being received by those who had not subscribed. These filters would be added or removed according to the subscription. As the number of television channels on these cable networks grew, the filter based approach became increasingly impractical.