Methods and apparatus for digital steganography

• US 9,542,864 B2
• Filed: 03/30/2015
• Issued: 01/10/2017
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: Salesforce.com, Inc.
• Original Assignee: Salesforce.com, Inc.
• Inventors: Fischer, Ronald
• Primary Examiner(s): Johns, Andrew W
• Application Number:
  US14/672,720
• Publication Number:
  US 20150206459A1
• Time in Patent Office: 652 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G09C 5/00 Ciphering apparatus or methods not provided for in the preceding groups, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages

Abstract

A computer-implemented digital steganography method includes providing a plurality of target data elements each comprising a sequence of digital bits, providing a plurality of source data elements each comprising a sequence of digital bits and has a specific start bit, and generating, according to a predefined extraction method, a mapping of each of the target data elements with a corresponding source data element. The mapping includes, for each target data element, a corresponding indice indicating the position of the specific start bit within a bitwise representation of the source data elements irrespective of the bitwise position of each of the source data elements.

Claims

1. A computer-implemented digital steganography method comprising:

providing a processor with a plurality of target data elements each comprising a sequence of digital bits;

providing the processor with a plurality of source data elements each comprising a sequence of digital bits; and

using the processor to generate, according to a predefined extraction method, a mapping of each of the target data elements with a corresponding source data element, wherein the mapping comprises, for each target data element, a corresponding indice indicating the position of a next occurrence of that target data element within the plurality of source data elements relative to a reference location within the plurality of source data elements.

2. The computer-implemented digital steganography method of claim 1, wherein providing a plurality of target data elements each comprising a sequence of digital bits comprises:

providing the processor with a target dataset having a binary form, the target dataset comprising;

the plurality of target data elements.

3. The computer-implemented digital steganography method of claim 2, wherein providing a plurality of source data elements each comprising a sequence of digital bits and a specific start bit for each source data element comprises:

providing the processor with a source dataset having a binary form, the source dataset comprising;

the plurality of source data elements.

4. The computer-implemented digital steganography method of claim 3, wherein using the processor to generate, according to a predefined extraction method, a mapping of each of the target data elements with a corresponding source data element comprises:

using the processor to map each of the target data elements in the target dataset with a corresponding source data element within the source dataset in accordance with the predefined extraction method to create a grille dataset.

5. The computer-implemented digital steganography method of claim 4, wherein each source data element comprises:

the sequence of digital bits such that the source dataset are represented in a bitwise representation having a specific start bit for each source data element, and wherein the grill dataset comprises;

a corresponding indice, for each target data element, indicating the position of the specific start bit within the bitwise representation of the source dataset, irrespective of the bitwise position of each of the source data elements.

6. The computer-implemented digital steganography method of claim 4, further comprising:

using the processor to encrypt the grille dataset to produce an encrypted grilled dataset.

7. The computer-implemented digital steganography method of claim 4, further comprising:

using the processor to transmitting the grille dataset over a computer network to a remote computing device, wherein the remote computing device has access to the predefined extraction method and the source dataset; and

using another processor to determine the target dataset based on the source dataset in accordance with the predefined extraction method.

8. The computer-implemented digital steganography method of claim 1, wherein the predefined extraction method is based information provided by a user.

a corresponding indice, for each target data element, indicating the position of the next occurrence of that target data element within the source dataset.

9. The computer-implemented digital steganography method of claim 8, wherein the position of the next occurrence is determined based on a location that is not the beginning of the source dataset.

10. The computer-implemented digital steganography method of claim 1, wherein the predefined extraction method is based in part on a key provided by a user.

11. The computer-implemented digital steganography method of claim 1, wherein the predefined extraction method comprises:

scanning through the source data elements to find ones of the source data elements that correspond to the target data elements.

12. The computer-implemented digital steganography method of claim 11, wherein a target dataset comprises the plurality of target data elements and wherein scanning comprises:

sequentially considering each target data element to find a next occurrence within the plurality of source data elements that matches that target data element, and

wherein mapping comprises;

adding an indicie to a grille dataset for each match between a target data element and one of the source data elements to generate a set of indices that can be used to reconstruct the target dataset.

13. The computer-implemented digital steganography method of claim 1, wherein the predefined extraction method is used as a cyclic-redundancy check to detect tampering of a source dataset that comprises the plurality of source data elements.

14. The computer-implemented digital steganography method of claim 1, wherein the predefined extraction method allows the plurality of target data elements to be reconstructed using the source dataset, and wherein:

a grille dataset comprises the mapping,

a source dataset comprises the plurality of source data elements,

a target dataset comprises the plurality of target data elements, and

wherein the grille dataset and source dataset are used to conceal the target dataset to any recipient that does not have access to the source dataset and the predefined extraction method, wherein the source dataset is not modified to conceal the target dataset.

15. The computer-implemented digital steganography method of claim 1, wherein one or more of the source data elements and the target data elements are digital image files.

16. The computer-implemented digital steganography method of claim 1, wherein one or more of the source data elements and the target data elements are digital music files.

17. The computer-implemented digital steganography method of claim 1, wherein one or more of the source data elements and the target data elements are binary large object (BLOB) files.

18. The computer-implemented digital steganography method of claim 1, wherein one or more of the source data elements and the target data elements are executable files.

19. A computing device comprising a processing system and a memory, wherein the memory comprises computer-executable instructions that, when executed by the processing system, cause the computing device to:

read a plurality of target data elements, wherein each target data element comprises;

a sequence of digital bits;

read a plurality of source data elements, wherein each source data element comprises;

a sequence of digital bits; and

generate, according to a predefined extraction method, a mapping of each of the target data elements with a corresponding source data element, wherein the mapping comprises, for each target data element, a corresponding indice indicating the position of a next occurrence of that target data element within the plurality of source data elements relative to a reference location within the plurality of source data elements.

20. The computing device of claim 19, wherein the computer-executable instructions that, when executed by the processing system, cause the computing device to:

read a target dataset having a binary form, the target dataset comprising;

the plurality of target data elements.

21. The computing device of claim 20, wherein the computer-executable instructions that, when executed by the processing system, cause the computing device to:

read a source dataset having a binary form, the source dataset comprising;

the plurality of source data elements.

22. The computing device of claim 21, wherein the computer-executable instructions that, when executed by the processing system, cause the computing device to:

map each of the target data elements in the target dataset with a corresponding source data element within the source dataset in accordance with the predefined extraction method to create a grille dataset.

23. The computing device of claim 22, wherein each source data element comprises:

the sequence of digital bits such that the source dataset are represented in a bitwise representation having a specific start bit for each source data element, and wherein the grill dataset comprises;

a corresponding indice, for each target data element, indicating the position of the specific start bit within the bitwise representation of the source dataset, irrespective of the bitwise position of each of the source data elements.

24. The computing device of claim 22, wherein the computer-executable instructions that, when executed by the processing system, cause the computing device to:

encrypt the grille dataset to produce an encrypted grilled dataset.

25. The computing device of claim 22, wherein the computer-executable instructions that, when executed by the processing system, cause the computing device to:

transmit the grille dataset over a computer network to a remote computing device that has access to the predefined extraction method and the source dataset, wherein the predefined extraction method is based in part on a key provided by a user.

26. The computing device of claim 19, wherein the predefined extraction method is based information provided by a user.

27. The computing device of claim 26, wherein the position of the next occurrence is determined based on a location that is not the beginning of the source dataset.

28. A method of encoding a plurality of target data elements, the method comprising:

using a processor to access a plurality of source data elements, wherein each source data element comprises;

a sequence of digital bits; and

using the processor to encode the plurality of target elements into a grille dataset, wherein the grille dataset includes a plurality of indices configured to map each of the target data elements with a corresponding source data element in accordance with a predefined extraction method, and wherein the mapping comprises, for each target data element, a corresponding indice indicating the position of a next occurrence of that target data element within the plurality of source data elements relative to a reference location within the plurality of source data elements.