Abstract: Methods and apparatus for scrambling and unscrambling a plurality of data streams having differing data, on a plurality of signal channels, are taught. The data streams may be television programs or other signal information, transmitted in a frame-by-frame manner with discrete synchronizing information, and where some of the data streams may be high priority such as pay-TV program material. All of the data streams are synchronized, an encryption key code is imposed on them, and a data package containing an identifier code for each data stream and a routing code is generated, so that each data stream is assigned at any instant of time to a specific one of the plurality of signal channels. The data package is encrypted in each data stream by being inserted at a specific place therein relative to the synchronizing information.