Multiple transform utilization and application for secure digital watermarking

• US 9,191,205 B2
• Filed: 04/22/2014
• Issued: 11/17/2015
• Est. Priority Date: 01/17/1996
• Status: Expired due to Fees

• Current Assignee: Wistaria Trading Inc.
• Original Assignee: Wistaria Trading Inc.
• Inventors: Moskowitz, Scott A.
• Primary Examiner(s): Shaw, Yin-Chen
• Assistant Examiner(s): King, John B
• Application Number:
  US14/258,118
• Publication Number:
  US 20140226812A1
• Time in Patent Office: 574 Days
• Field of Search: 380/203, 380/252, 380/264
• US Class Current: 1/1
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 1/0057 Compression invariant watermarking
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0053 Embedding of the watermark in the coding stream, possibly without decoding; Embedding of the watermark in the compressed domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• CPC Class Codes: G06T 2201/0063 in relation to collusion attacks, e.g. collusion attack resistant
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/043 of tables, e.g. lookup, substitution or mapping
• CPC Class Codes: H04L 2209/046 of operations, operands or results of the operations
• CPC Class Codes: H04L 9/0819 Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) network architectures or network communication protocols for key distribution in a packet data network H04L63/062
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04N 1/3216 using Fourier transforms
• CPC Class Codes: H04N 1/32187 with selective or adaptive application of the additional information, e.g. in selected frequency coefficients
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/324 : Selecting a particular authentication information from amongst a plurality of different authentication information

Abstract

Multiple transform utilization and applications for secure digital watermarking In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.

Claims

1. A method for encoding a message and scale information into digital information corresponding to an audio signal, comprising:

(1) storing in digital memory of an encoder, digital information defining the message;

(2) receiving in said encoder, a digital audio signal block;

wherein said digital audio signal block is a digital representation of one of a set of temporally sequential segments of the audio signal;

(3) transforming, using said encoder and a transform, said digital audio signal block into the frequency domain, thereby defining a first set of amplitudes, wherein each one of said first set of amplitudes is associated with a corresponding one of a set of sequential frequencies ranges;

(4) identifying, using said encoder and said first set of amplitudes, an amplitude based frequency range subset of said corresponding set of sequential frequency ranges; and

(5) encoding, using said encoder and a primary mask of a key, at least some of said amplitude based frequency range subset, by altering the amplitude associated with the corresponding frequency range;

(6) receiving, in said encoder, a digital audio signal block, and wherein the digital audio signal block received in the encoder in step (6) corresponds to a next temporally sequential segment of the audio signal;

(7) repeating steps (3)-(5) on the digital audio signal bloc received in the encoder in step (6), followed by repeating step (6);

(8) repeating step (7) for the remainder of the digital audio signal blocks corresponding to the temporally sequential segments of the audio signal; and

(9) said encoder storing, in the key, said at least some of said amplitude based frequency range subset, and corresponding amplitudes, in association with one another; and

(10) said encoder storing, in the key, a digital representation of a sequence of the original audio signal.

2. The method of claim 1 wherein said sequence of the original audio signal comprises information defining the time duration of said sequence.

3. The method of claim 1 further comprising (11) storing the duration of said original audio signal in the key.

4. The method of claim 1 further comprising:

a decoder descaling an audio signal by matching a portion of the audio signal to said sequence of the original signal to determine a scale associated with said audio signal, and descaling the audio signal based upon the determined scale to generate a descaled audio signal; and

decoding the message from the descaled audio signal using the frequency ranges and corresponding amplitudes stored in the key.

5. The method of claim 1 further comprising a certification computer comprising computer memory storing the key in the computer memory;

and certifying audio content by descaling and decoding based upon the sequence of the original audio signal stored in the key and the frequency ranges and corresponding amplitudes stored in the key.

6. The method of claim 1 further comprising said encoder tracking the sequential number of digital audio signal blocks it acquires by storing a window counter value in a window counter.

7. The method of claim 6 further comprising said encoder setting said window counter value to zero when said window counter value reaches a specified integer value.

8. The method of claim 1 further comprising said encoder encoding a start of message delimeter in said digital information.

9. A method for encoding a message and scale information into digital information corresponding to an image, comprising:

(1) storing, in digital memory of an encoder, digital information defining the message;

(2) receiving, in said encoder, a digital signal image block;

wherein said digital signal image block is a digital representation of one of a set of ordered segments of the image;

(3) transforming, using said encoder and a transform, said digital signal image block into the spatial frequency domain, thereby defining a fist set of amplitudes, wherein each one of said first set of amplitudes is associated with a corresponding one of a set of ordered frequency ranges;

(4) identifying, using said encoder and said first set of amplitudes, an amplitude based frequency range subset of said corresponding set of ordered frequency ranges;

(5) encoding, using said encoder and a primary mask of a key, at least some of said amplitude based frequency range subset, by altering the amplitude associated with the corresponding frequency range;

(6) receiving, in said encoder, a digital audio signal block;

wherein the digital image signal block received in the encoder in step (6) corresponds to next one of the ordered segments of the image;

(7) repeating steps (3)-(5) on the digital audio signal block received in the encoder in step (6), followed by repeating step (6);

(8) repeating step (7), for the remainder of the digital signal image blocks corresponding to the ordered segments of the image; and

(9) said encoder storing, in the key, said at least some of said amplitude based frequency range subset, and corresponding amplitudes, in association with one another; and

(10) said encoder storing, in the key, a digital representation of a portion the image.

10. The method of claim 9 wherein the digital representation of the image comprises information defining the spatial dimensions of the image.

11. The method of claim 9 further comprising (11) the encoder storing in the key, at least one spatial dimension of the digital representation of the image.

12. The method of claim 9 further comprising:

a decoder descaling an image signal by matching a portion of the image signal to said digital representation of said portion of the image, to determine a scale associated with said image signal, and descaling the image signal based upon the determined scaled to generate a descaled image signal; and

decoding the message from the descaled image signal using the frequency ranges and corresponding amplitudes stored in the key.

13. The method of claim 9 further comprising:

a certification computer comprising computer memory storing the key in the computer memory; and

said certification computer certifying image signals by;

descaling and decoding based upon the digital representation of the portion of the image sequence stored in the key and the frequency ranges and corresponding amplitudes stored in the key; and

determining whether the information decoded from the image signal corresponds to said message.

14. The method of claim 9 further comprising said encoder tracking the sequential number of digital signal image blocks it acquires by storing a window counter value in a window counter.

15. The method of claim 14 further comprising said encoder setting said window counter value to zero when said window counter value reaches a specified integer value.

16. The method of claim 9 further comprising said encoder encoding a start of message delimeter in said digital information.