Digital communication system including an error correcting encoder/decoder and a scrambler/descrambler Patent #: 4639548
ApplicationNo. 357713 filed on 12/14/1994
US Classes:713/176, Authentication by digital signature representation or digital watermark380/30, Public key380/201, Copy protection or prevention380/217Having compression (e.g., MPEG)
ExaminersPrimary: Gregory, Bernarr E.
Attorney, Agent or Firm
International ClassH04L 009/00
AbstractArbitrary digital information is embedded within a stream of digital data, in a way that avoids detection by a casual observer and that allows a user to determine whether the digital data have been modified from their intended form. The embedded information may only be extracted as authorized and may be used to verify that the original digital data stream has not been modified.