- In scrambling, a data stream is scrambled according to a specified mathematical polynomial. In principle, scrambling is performed by a pseudorandom generator of length 2expn-1 with n feedback stages. This technique is used to avoid consistent signal patterns and provides a more uniform distribution of signal energy over the entire frequency range. Scrambling prevents signal energy from being concentrated in a narrow, high-amplitudefrequency band, as would occur with long repetitive bit patterns such as the idle signal without scrambling. Scrambling can improve the characteristics of non- code-transparent transmission methods. Scramblers are used in modem technology, baseband technology and in the transmission of radio and television signals. Most V-series modems use the scrambling technique. In local area networks, this technique is used in transceivers.
- In smart cards, scrambling is the random assignment of buses. In this case, the various buses of the microcontroller can no longer be assigned to each other in terms of their function, since the address bus, the data bus and the control bus are mixed with each other. This mixing can vary from chip card to chip card.