Standard time and frequency signal service (STFS): In the United States, standardtime and frequency signals, broadcast on very precise carrier frequencies by the U.S. Naval Observatory and the National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards (NBS).
... (CSS) employed by the DVD Consortium[?] on movie DVD disks. The data on the DVD is encrypted so that it can only be decoded and viewed using an encryption key, which the ...