Methods, systems, and computer readable media for preventing software piracy and protecting digital documents using same

• US 9,275,203 B1
• Filed: 02/03/2014
• Issued: 03/01/2016
• Est. Priority Date: 02/03/2014
• Status: Active Grant

• Current Assignee: Purdue Research Foundation (Purdue University)
• Original Assignee: Purdue Research Foundation (Purdue University)
• Inventors: Rice, John R.
• Primary Examiner(s): Abyaneh, Ali
• Assistant Examiner(s): Wade, Shaqueal
• Application Number:
  US14/171,398
• Time in Patent Office: 757 Days
• US Class Current: 1/1
• 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: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings

Abstract

The subject matter described herein includes methods, systems, and computer readable media for preventing software piracy. One method includes specifying at least one codemark that is intrinsic to a computing system. The method further includes inserting guard code in an application. The guard code including a first code portion that uses a codemark and produces an output that depends on a value of the codemark and a second code portion that uses the output of the first code portion. The method further includes executing the first and second code portions and selectively triggering a protective action based on the output of the second code portion. Multiple types, styles, and frequencies of guard codes can be used to provide in-depth, long lasting, and strong protection.

Claims

1. A method for preventing software piracy, the method comprising:

specifying a codemark that is intrinsic to a computing system;

providing an application with a first embedded silent guard, the first embedded silent guard including a first portion that uses the codemark and produces a guarded value that depends on the codemark, the first silent guard further including a second portion that uses the guarded value as a value for an ordinary program variable in the application and that produces an output that depends on the guarded value;

executing the first and second portions, wherein the second portion causes the application to malfunction or take another protective action when the guarded value is not equal to an expected value; and

providing a second silent guard embedded in the application.

2. The method of claim 1 wherein the first silent guard is located in a portion of the application that is not executed every time the application is executed.

3. The method of claim 1 wherein the second silent guard computes, independently from the first silent guard, a second guarded value.

4. The method of claim 3 wherein the second silent guard includes a first portion that computes the second guarded value and a second portion that uses the second guarded value as a value for an ordinary program variable.

5. The method of claim 1 wherein the first and second silent guards are configured to operate at different times.

6. The method of claim 1 wherein the first silent guard computes a new value for a constant used by the application.

7. The method of claim 1 wherein the codemark comprises a user specific value.

8. The method of claim 7 wherein the codemark is embedded in the application.

9. The method of claim 7 wherein the codemark is located outside of the application.

10. A system for preventing software piracy, the system comprising:

a computing system including at least one processor;

a codemark intrinsic to the computing system; and

an application configured to execute on the processor, wherein the application includes a first silent guard including a first portion that uses the codemark and produces a guarded value that depends on the codemark, the first silent guard including a second portion that uses the guarded value as a value for an ordinary program variable in the application and that produces an output that depends on the guarded value, wherein the application is configured to execute the first and second portions, wherein the second portion causes the application to malfunction or take another protective action when the guarded value is not equal to an expected value and wherein the application includes a second silent guard embedded in the application.

11. The system of claim 10 wherein the first silent guard is located in a portion of the application that is not executed every time the application is executed.

12. The system of claim 10 wherein the second silent guard computes, independently from the first silent guard, a second guarded value.

13. The system of claim 12 wherein the second silent guard includes a first portion that computes the second guarded value and a second portion that uses the second guarded value as a value for an ordinary program variable.

14. The system of claim 10 wherein the first and second silent guards are configured to operate at different times.

15. The method of claim 10 wherein the first silent guard computes a new value for a constant used by the application.

16. The system of claim 10 wherein the codemark comprises a user specific value.

17. The system of claim 16 wherein the codemark is embedded in the application.

18. The system of claim 16 wherein the codemark is located outside of the application.

19. A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer control the computer to perform steps comprising:

storing a codemark on a computing system;

executing an application with a first embedded silent guard, the first silent guard including a first portion that uses the codemark and produces a guarded value that depends on the codemark, the first silent guard further including a second portion that uses the guarded value as a value for an ordinary program variable in the application, wherein the ordinary program variable produces an output that depends on the first guarded value;

executing the first and second portions, wherein the second portion causes the application to malfunction or take another protective action when the guarded value is not equal to an expected value and wherein the application includes a second embedded silent guard.

20. A method for preventing unauthorized access to a document, the method comprising:

encrypting a digital document using an encryption algorithm;

installing the encrypted digital document and a shared secret for decrypting the digital document into a reader application such that the digital document can only be viewed using the reader application and the shared secret; and

tying the reader application to a computing system using a first silent guard and a codemark, wherein the first silent guard includes a first portion that uses the codemark and produces a guarded value that depends on the codemark, the first silent guard further includes a second portion that uses the guarded value as a value for an ordinary program variable in the reader application and that produces an output that depends on the guarded value, wherein the second portion causes the reader application to malfunction or take another protective action when the guarded value is not equal to an expected value and wherein a second silent guard is embedded in the reader application.

21. The method of claim 20 wherein encrypting the document includes using an encryption algorithm and a key, wherein the reader application requires a password or the key before the document can be opened using the reader application.

22. The method of claim 20 wherein the second silent guard computes, independently from the first silent guard, a second guarded value.

23. The method of claim 22 wherein the second silent guard includes a first portion that computes the second guarded value and a second portion that uses the second guarded value as a value for an ordinary program variable.

24. The method of claim 20 wherein the first and second silent guards are configured to operate at different times.

25. The method of claim 20 wherein the first silent guard computes a new value for a constant used by the application.

26. The method of claim 20 wherein the codemark comprises a user specific value.

27. The method of claim 26 wherein the codemark is embedded in the reader application.

28. The method of claim 26 wherein the codemark is located outside of the reader application.

29. A system for preventing unauthorized access to an electronic document, the system comprising:

at least one hardware processor coupled to a memory, the memory storing a document protection module that is executed by the at least one hardware processor;

a reader application for displaying digital documents on a computing system;

the document protection module associated with the reader application for encrypting a digital document using an encryption algorithm and for installing the encrypted digital document and a shared secret for decrypting the digital document into a reader application such that the digital document is only viewed using the reader application and the shared secret; and

a first silent guard associated with the reader application, wherein the first silent guard includes a first portion that uses a codemark and produces a guarded value that depends on the codemark, the first silent guard further includes a second portion that uses the guarded value as a value for an ordinary program variable in the application and that produces an output that depends on the guarded value, wherein the second portion causes the reader application to malfunction or take another protective action when the guarded value is not equal to an expected value and wherein a second silent guard is embedded in the reader application.

30. The system of claim 29 wherein the document protection module is configured to encrypt the document using an encryption algorithm and a key, wherein the reader application requires a password or the key before the document can be opened using the reader application.

31. The system of claim 29 wherein the second silent guard is configured to compute, independently from the first silent guard, a second guarded value.

32. The system of claim 31 wherein the second silent guard includes a first portion that computes the second guarded value and a second portion that uses the second guarded value as a value for an ordinary program variable.

33. The system of claim 29 wherein the first and second silent guards are configured to operate at different times.

34. The method of claim 29 wherein the first silent guard computes a new value for a constant used by the application.

35. The system of claim 29 wherein the codemark comprises a user specific value.

36. The system of claim 29 wherein the codemark is embedded in the reader application.

37. The system of claim 29 wherein the codemark is located outside of the reader application.

38. The system of claim 29 wherein the reader application includes a plurality of sub-readers, each sub-reader being tied to a specific document.

39. A non-transitory computer readable medium having stored thereon executable instructions that when executed by a processor of a computer control the computer to perform steps comprising:

encrypting a digital document using an encryption algorithm;

installing the encrypted digital document and a shared secret for decrypting the digital document into a reader application such that the digital document is only viewed using the reader application and the shared secret; and

tying the reader application to a computing system using a silent guard and a codemark, wherein the silent guard includes a first portion that uses the codemark and produces a guarded value that depends on the codemark, the silent guard further includes a second portion that uses the guarded value as a value for an ordinary program variable in the application and that produces an output that depends on the guarded value, wherein the second portion causes the reader application to malfunction or take another protective action when the guarded value is not equal to an expected value and wherein the reader application includes an embedded second silent guard.