Patent ID: 7007166

Claim:
A method of applying a digital watermark to a content signal with a plurality of functions, including the input of at least a random key and a digital watermark, the method comprising the steps of: (1) providing a random key generated by the following steps: (a) generating a random sequence of binary numbers; (b) generating information describing the application of the random sequence to the content signal, wherein the information comprises a sample window size, a signal encoding level, and at least one of the following two groups: time delimiters describing segments of the content signal; frequency delimiters describing frequency bands of the content signal; and (c) combining the random sequence and the generated information to form a random key; (2) providing a digital watermark to be embedded; and (3) embedding the digital watermark using at least the random key and the plurality of functions to produce a uniquely watermarked content signal.