Optimization methods for the insertion, protection, and detection of digital watermarks in digital data

• US 20090037740A1
• Filed: 07/09/2008
• Published: 02/05/2009
• Est. Priority Date: 07/02/1996
• Status: Active Grant

• Current Assignee: Wistaria Trading Inc.
• Original Assignee: Wistaria Trading Inc.
• Inventors: Moskowitz, Scott A.
• Granted Patent: US 7,987,371 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/603 Digital right managament [DRM]
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467

Abstract

Disclosed herein are methods and systems for encoding digital watermarks into content signals. Also disclosed are systems and methods for detecting and/or verifying digital watermarks in content signals. According to one embodiment, a system for encoding of digital watermark information includes: a window identifier for identifying a sample window in the signal; an interval calculator for determining a quantization interval of the sample window; and a sampler for normalizing the sample window to provide normalized samples. According to another embodiment, a system for pre-analyzing a digital signal for encoding at least one digital watermark using a digital filter is disclosed. According to another embodiment, a method for pre-analyzing a digital signal for encoding digital watermarks comprises: (1) providing a digital signal; (2) providing a digital filter to be applied to the digital signal; and (3) identifying an area of the digital signal that will be affected by the digital filter based on at least one measurable difference between the digital signal and a counterpart of the digital signal selected from the group consisting of the digital signal as transmitted, the digital signal as stored in a medium, and the digital signal as played backed. According to another embodiment, a method for encoding a watermark in a content signal includes the steps of (1) splitting a watermark bit stream; and (2) encoding at least half of the watermark bit stream in the content signal using inverted instances of the watermark bit stream. Other methods and systems for encoding/decoding digital watermarks are also disclosed.

Claims

1-88. -88. (canceled)

89. A method for generating a plurality of unique copies of a digital data signal, comprising:

obtaining the digital data signal;

identifying a plurality of candidate bits in the digital data signal that can be manipulated during encoding;

obtaining a digital watermark message to be encoded based on at least one predetermined criterion; and

encoding the digital watermark message in the plurality of candidate bits.

90. The method of claim 89, wherein the step of identifying candidate bits of the digital data signal to be manipulated comprises:

generating a psychoacoustic model of the digital data signal.

91. The method of claim 89, wherein the step of identifying candidate bits of the digital data signal to be manipulated comprises:

generating a psychovisual model of the digital data signal.

92. The method of claim 89, wherein the digital data signal comprises compressed digital data.

93. The method of claim 89, wherein the step of obtaining a digital watermark message comprises:

generating a unique digital watermark message for each copy.

94. The method of claim 89, wherein the criterion are selected from the group consisting of a geographical territory, a transaction identification, an individual identification, a use limitation, and a signal domain.

95. The method of claim 89, wherein the digital watermark message is encoded in a subset of the plurality of candidate bits identified.

96. The method of claim 89, wherein the plurality of candidate bits that are encoded with the digital watermark message have a relationship that creates additional uniqueness of the digital watermark message.

97. The method of claim 96, wherein the relationship is at least one of a sequential relationship, a linear relationship, and a logically-ordered relationship.

98. The method of claim 89, wherein a subset of the plurality of the candidate bits share at least one function.

99. The method of claim 98, wherein the function is selected from the group consisting of mapping, error correction, and signal processing.

100. The method of claim 89 further comprising:

selectively adding noise to the digital data signal.

101. A process for generating a plurality of unique copies of a digital signal, comprising:

obtaining a digital signal;

identifying at least one candidate bit of the digital signal that will be manipulated during embedding;

generating a key based on at least one predetermined criterion; and

manipulating the at least one candidate bit with the key.

102. The process of claim 101, wherein the step of identifying at least one candidate bit of the digital signal to be manipulated comprises:

generating a psychoacoustic model of the digital signal.

103. The process of claim 101, wherein the step of identifying at least one candidate bit of the digital signal to be manipulated comprises:

generating a psychovisual model of the digital signal.

104. The process of claim 101, wherein the digital signal comprises compressed digital data.

105. The process of claim 101, wherein the step of generating a key comprises:

generating a unique key for each unique copy of the digital signal.

106. The process of claim 101, wherein the criterion are selected from the group consisting of a geographical territory, a transaction identification, an individual identification, a use limitation, and a signal domain.

107. The process of claim 101, wherein a plurality of candidate bits is identified.

108. The process of claim 107, wherein a subset of the plurality of candidate bits is manipulated with a key.

109. The process of claim 107, wherein a subset of the plurality of the candidate bits are selected based upon their ability to survive a predetermined test of robustness.

110. An article of manufacture comprising a machine readable medium, having thereon stored instructions adapted to be executed by a processor, which instructions when executed result in a process comprising:

obtaining a model for a data signal wherein the model describes watermarking parameters;

generating a watermark to be embedded in the data signal based on at least one criterion; and

embedding the generated watermark using the obtained model of the data signal to create a watermarked data signal.

111. The article of manufacture of claim 110, wherein the step of obtaining a model of the data signal comprises:

generating a psychoacoustic model for the data signal.

112. The article of manufacture of claim 110, wherein the step of obtaining a model of the data signal comprises:

retrieving a stored psychoacoustic model for the data signal.

113. The article of manufacture of claim 110, wherein the step of obtaining a model of the digital data signal comprises:

generating a psychovisual model for the data signal.

114. The article of manufacture of claim 110, wherein the step of obtaining a model of the digital data signal comprises:

retrieving a stored psychovisual model for the data signal.

115. The method of claim 110, wherein the criterion are selected from the group consisting of a geographical territory, a transaction identification, an individual identification, a use limitation, and a signal domain.

116. An article of manufacture comprising a machine readable medium, having thereon stored instructions adapted to be executed by a processor, which instructions when executed

result in a process comprising:

receiving a data signal;

identifying a plurality of candidate bits in the data signal that can be manipulated during encoding;

generating at least one watermark to be encoded based on at least one criterion;

determining candidate bits to manipulate; and

encoding the at least one watermark in the determined candidate bits.

117. The article of manufacture of claim 116, wherein the at least one criterion includes at least one characteristic of the data signal.

118. The article of manufacture of claim 116, wherein the step of determining candidate bits to manipulate comprises:

selecting candidate bits that provide optimal locations for the watermark.

119. The article of manufacture of claim 116, further comprising the step of:

inverting at least one watermark out of a plurality of encoded watermarks.

120. The article of manufacture of claim 116, further comprising the step of:

decoding the at least one watermark from the data signal.

121. The article of manufacture of claim 120, wherein the step of decoding the at least one watermark from the data signal comprises:

degrading the watermarked data signal responsive to an unauthorized attempt to decode the watermark from the data signal.

122. The article of manufacture of claim 120, wherein the step of decoding the at least one watermark from the data signal comprises:

degrading the watermarked data signal responsive to fewer than all encoded watermarks being decoded from the data signal.

123. The article of manufacture of claim 120, wherein the step of decoding the at least one watermark from the data signal is asymmetric.

124. The article of manufacture of claim 116, wherein a key corresponding to each of the at least one watermark comprises a greater number of bits than the corresponding watermark.

125. The article of manufacture of claim 116, wherein a key corresponding to each of the at least one watermark comprises the same number of bits as the corresponding watermark.