Nagravision

Nagravision (or Nagra Kudelski or simply Nagra) is a company of the Kudelski Group that develops conditional access systems for digital cable and satellite television.

In this line-shuffling system, bottom 32 lines of the PAL TV signal are shifted in time by one video field, and read out in permuted order under the control of a pseudorandom number generator.

A smartcard security microcontroller (in a key-shaped package) decrypts data that is transmitted during the blanking intervals of the TV signal mixed with teletext and extracts the random seed value which contains present line combination needed for reverting the picture back.

The system also permitted the audio signal to be modulated at 12.8 kHz using a frequency mixer.

Nagravision has been adopted all over the world as a conditional access system, with providers: