Security based on subliminal and supraliminal channels for data objects

• US 7,127,615 B2
• Filed: 09/20/2001
• Issued: 10/24/2006
• Est. Priority Date: 09/20/2000
• Status: Active Grant

• Current Assignee: Wistaria Trading Inc.
• Original Assignee: Blue Spike, Inc.
• Inventors: Moskowitz, Scott A.
• Primary Examiner(s): Louis-Jacques, Jacques
• Assistant Examiner(s): Lipman, Jacob
• Application Number:
  US09/956,262
• Publication Number:
  US 20020056041A1
• Time in Patent Office: 1,860 Days
• Field of Search: 713/176, 726/26, 726/32, 726/33
• US Class Current: 713/176
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/16 Program or content traceability, e.g. by watermarking
• CPC Class Codes: G06Q 20/3823 combining multiple encryption tools for a transaction
• CPC Class Codes: G06Q 30/06 Buying, selling or leasing transactions
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management
• CPC Class Codes: H04L 2463/102 applying security measure for e-commerce
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions

Abstract

This invention relates to security for data objects; more particularly, the present invention relates to improved security based on subliminal and supraliminal channels for data objects.

In one embodiment, a method for protecting a data signal comprises: providing a data signal to be encoded; using a first predetermined key to encode a first set of independent data into the data signal imperceptibly; and using a second predetermined key to encode a second set of independent data into the data signal perceptibly.

In another embodiment, a method of protecting a data object comprises: steganographically encoding a subset of candidate bits in a digitized sample stream; perceptibly manipulating data in the digitized sample stream; and combining the imperceptible and perceptible data changes to create a secure/unique digital sample stream.

In yet another embodiment, a method for securing a data signal comprises: preanalyzing said data signal for candidate watermark/signature bits; steganographically encoding independent data into the data signal into a subset of the candidate watermark bits, at least one time; and encoding the data signal subsequently with a perceptible technique.

In yet another embodiment, a method of protecting a data signal comprises: imperceptibly embedding data using a watermarking technique; perceptibly signing the data using the receiver'"'"'s public key; encrypting the data signal using the receiver'"'"'s public key and the private key used to watermark the signal; and enabling a receiver to authenticate/verify (separate steps) the data signal while connected to a communications channel.

Claims

1. A method for protecting a data signal comprising:

providing an original data signal to be encoded;

predetermining a perceptibility threshold for said encoding;

predeterminig at least one dependency between a first set of independent data and a second set of independent data;

using a first cryptographic key to encode the first set of independent data into the data signal imperceptibly below the perceptibility threshold; and

using a second cryptographic key to encode the second set of independent data into the data signal perceptibly above the perceptibility threshold.

2. The method of claim 1, wherein the imperceptibly encoded data comprises a digital watermark associated with at least one cryptographic key.

3. The method of claim 1, wherein the step of using the first cryptographic key to encode data into the data signal imperceptibly comprises using the first cryptograhic key to encode the first set of independent data into the data signal imperceptibly below the perceptibility threshold in a predetermined location in at least one of the following domains:

frequency;

time;

spatial; and

bit depth.

4. The method of claim 1, wherein the step of using the first cryptographic key to imperceptibly encode data into the data signal comprises using a transfer function to imperceptibly encode the first set of independent data below the perceptibility threshold into the data signal.

5. The method of claim 1, wherein the step of using the first cryptographic key to imperceptibly encode data into the data signal comprises using a symmetric cipher to imperceptibly encode the first set of independent data below the perceptibility threshold into the data signal.

6. The method of claim 1, wherein the perceptibly encoded data above the perceptibility threshold and the imperceptibly encoded data below the perceptibility threshold are encoded such that there is a logical relationship between the perceptibly encoded data and the imperceptibly encoded data.

7. The method of claim 1, wherein the perceptibly encoded data above the perceptibility threshold and the imperceptibly encoded data below the perceptibility threshold are encoded such that there is a hierarchical relationship between the perceptibly encoded data and the imperceptibly encoded data.

8. The method of claim 1, further comprising:

hashing the first set of independent data and associating the hash value of the first set of independent data with the first cryptographic key; and

hashing the second set of independent data and associating the hash value of the second set of independent data with the second cryptographic key.

9. The method of claim 1, further comprising:

hashing the first set of independent data and associating the hash value of the first set of independent data with the second cryptographic key; and

hashing the second set of independent data and associating the hash value of the second set of independent data with the first cryptograghic key.

10. The method of claim 1, wherein the step of using the second cryptographic key to perceptibly encode data above the perceptibility threshold into the data signal comprises:

hashing the second set of independent data;

associating the hash value of the second set of independent data with the second set of independent data; and

using the second cryptographic key to encode the hash value of the second set of independent data perceptibly above the perceptibility threshold into the data signal.

11. The method of claim 1, wherein the first set of independent data is identical to the second set of independent data.

12. The method of claim 1, further comprising:

determining at least one difference between the original data signal and the encoded data signal;

hashing the at least one difference between the original data signal and the encoded data signal; and

associating the hash value of the at least one difference between the original data signal and the encoded data signal to at least one of the first cryptographic key and the second cryptographic key.

13. The method of claim 1, further comprising:

removing the data that has been perceptibly encoded above the perceptibility threshold into the data signal.

14. The method of claim 1, wherein the step of using the second cryptographic key to perceptibly encode data above the perceptibility threshold into the data signal comprises using the second cryptographic key to encode the first set of independent data into the data signal such that the data signal is degraded perceptibly to a predetermined amount of degradation.

15. The method of claim 1, wherein the second set of independent data includes information about the first cryptographic key to permit the removal of the data that was imperceptibly encoded below the perceptibility threshold into the data signal.