------------713/176 that are used for authentication by employing a short (even Single-bit)
watermark vector to make the watermark and using the message needed for the
authentication to deter mine where the watermark is located in the digital repre Sentation.
Authentication of a digital representation is done by determining whether the watermark is
present in the digital representation. In another technique, detection of the presence of a
watermark is used to determine what areas of a digital representation have been Subject to …

Techniques for watermarking sequences of digital represen tations and detecting the
watermarks in the digital represen tations. One of the techniques is used when the message
that is contained in a watermark belonging to a digital represen tation that is derived from an
original watermarked digital representation cannot be decoded. The technique obtains
information about the watermark by comparing the water mark vector for the watermark that
cannot be decoded with a replica of the watermark vector from the original water marked …