Steganographic method and device
First Claim
Patent Images
1. A method for steganographically protecting a digital signal comprising the step of:
- a) providing a carrier signal that has been encoded with independent information;
b) using a stega-cipher to steganographically decode independent information including a digital watermark from the carrier signal;
c) generating a first derivative encoded signal representing the original carrier signal combined with the encoded independent information, including the digital watermark, wherein the first derivative encoded signal is an arbitrarily close approximation of the original carrier signal; and
d) modifying the first derivative encoded signal to produce a second derivative encoded signal, wherein the second derivative encoded signal differs from the original carrier signal by a greater degree than the first derivative encoded signal differs from the original carrier signal, as measured by an arbitrary signal metric.
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Abstract
An apparatus and method for encoding and decoding additional information into a stream of digitized samples in an integral manner. The information is encoded using special keys. The information is contained in the samples, not prepended or appended to the sample stream. The method makes it extremely difficult to find the information in the samples if the proper keys are not possessed by the decoder. The method does not cause a significant degradation to the sample stream. The method is used to establish ownership of copyrighted digital multimedia content and provide a disincentive to piracy of such material.
365 Citations
35 Claims
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1. A method for steganographically protecting a digital signal comprising the step of:
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a) providing a carrier signal that has been encoded with independent information; b) using a stega-cipher to steganographically decode independent information including a digital watermark from the carrier signal; c) generating a first derivative encoded signal representing the original carrier signal combined with the encoded independent information, including the digital watermark, wherein the first derivative encoded signal is an arbitrarily close approximation of the original carrier signal; and d) modifying the first derivative encoded signal to produce a second derivative encoded signal, wherein the second derivative encoded signal differs from the original carrier signal by a greater degree than the first derivative encoded signal differs from the original carrier signal, as measured by an arbitrary signal metric.
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2. A method for steganographically protecting a digital signal comprising the step of:
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a) providing a carrier signal; b) using a stega-cipher to steganographically encode independent information including a digital watermark into the carrier signal; c) selecting a mask set, said mask set including one or more random or pseudo-random series of bits, referred to as masks; d) selecting a random or pseudo-random start of message delimiter; and e) selecting independent information to be encoded. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for steganographically protecting a digital signal comprising the steps of:
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a) providing a carrier signal that has been encoded with independent information; b) using a stega-cipher to steganographically decode independent information including a digital watermark from the carrier signal; c) selecting a mask set, said mask set including one or more random or pseudo-random series of bits, referred to as masks; d) selecting a random or pseudo-random start of message delimiter; and e) selecting an input sample stream to be decoded. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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Specification