PROTECTING SOFTWARE FROM UNAUTHORIZED USE BY CONVERTING SOURCE CODE MODULES TO BYTE CODES

• US 20060271921A1
• Filed: 06/30/2006
• Published: 11/30/2006
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Pace Antipiracy
• Original Assignee: Pace Antipiracy
• Inventors: Fontana, Joseph, Anderson, Eric C., Cronce, Paul A.
• Granted Patent: US 7,730,542 B2
• Time in Patent Office: Days
• US Class Current: 717/151
• CPC Class Codes: G06F 21/14 against software analysis or reverse engineering, e.g. by obfuscation

Abstract

A method for anti-piracy protection of a software application by obfuscation of the execution of portions of the applications code is described. The method includes providing a language specification and library to implement the functions of the language, providing a compiler to translate the language into byte codes, and providing an interpreter to execute the byte codes using the library. The method further includes providing the language specifications, library, compiler, interpreter, and instructions to a software publisher, where the software publisher embeds the library and interpreter in the application to be protected, and selects and prepares application code segments for processing into byte codes by the compiler. The application is then executed using the embedded library and interpreter, where the execution of the application is obfuscated by the use of byte codes.

Claims

1. A method for providing anti-piracy protection for a software application, comprising:

providing a language specification for a programming language, a library to implement the language, a compiler to compile the language into byte codes, and an interpreter to execute the byte codes using the library; and

providing the language specification, library, compiler, and interpreter, in conjunction with instructions to a software publisher, wherein the software publisher embeds the library and interpreter in the application, selects and prepares application code portions for conversion to byte codes, compiles the prepared portions into byte codes using the compiler, and executes the application using the interpreter and library, wherein during execution of the software application, the interpreter interprets the byte codes, thus obfuscating the application'"'"'s execution path.

2. The method of claim 1 further including providing the language specification, compiler, library, interpreter, and instructions as part of an anti-piracy protection wrapping toolset.

3. The method of claim 1 further including encrypting the byte codes using a product private key wherein the byte codes can only be decrypted and function properly using a decryption function included in the interpreter using the product public key.

4. The method of claim 1 further including randomizing the byte codes using a reversible mathematical function, and providing a function within the interpreter to reverse the randomization of the byte codes, wherein the byte codes are different for each copy of the application.

5. The method of claim 1 further including reordering of library routines by using an initialization vector generated from publisher information as a seed for a randomizing function, whereby different copies of the interpreter and library are unique for each publisher, and therefore assist in obfuscation of an operation of the interpreter.

6. The method of claim 1 further including reordering of a address table used by the interpreter for accessing the library routines by using a initialization vector generated from publisher information as a seed for a randomizing function, and using a lookup table to translate the byte codes from the compiler to match the reordering, whereby the byte code values are unique for different publishers and therefore assist in obfuscation of an operation of the interpreter.

7. The method of claim 1 further including modifying constants generated by the compiler by applying a reversible mathematical operation to the constants, and providing the reversible mathematical operation to reverse the modification of the constants within the interpreter, thereby assisting in the obfuscation of an operation of the interpreter.

8. The method of claim 7 wherein the reversible mathematical operation is an exclusive OR operation on an initialization vector generated from publisher information, and wherein the initialization vector is stored with the interpreter so that the vector can be utilized to reverse the modification of the constant during interpreter execution.

9. A method for providing anti-piracy protection for a software application on a server, comprising:

providing a language specification for a programming language, a library to implement the language, a compiler to compile the language into byte codes, and an interpreter to execute the byte codes using the library;

providing the language specification and instructions to a software publisher with instructions for instructing the software publisher on how to select portions of code from the application to be protected, and how to prepare the selected segments and the application for processing on the server;

providing the server with the compiler, library, interpreter, and a server application for receiving the software application to be protected and the prepared code segments from the publisher, wherein the server application protects the software application by;

compiling the selected segments into byte codes using the compiler,

embedding the byte codes generated by the compiler in the application, thereby obfuscating the selected segments, and

embedding the library and interpreter in the application to support run-time interpretation of the compiled byte codes, thereby obfuscating the selected segments.

10. The method of claim 9 further including the step of incorporating in the server application an anti-piracy protection wrapping feature to wrap the application to be protected wherein other anti-piracy protection methods are applied to the application in addition to byte code obfuscation.

11. The method of claim 9 further including the step of encrypting the byte codes using a product private key wherein the byte codes can only be decrypted and function properly using a decryption function included in the interpreter using the product public key.

12. The method of claim 9 further including randomizing the byte codes using a reversible mathematical function, and providing a function within the interpreter to reverse the randomization of the byte codes, wherein the byte codes are different for each copy of the application.

13. The method of claim 9 further including reordering of library routines by using an initialization vector generated from publisher information as a seed for a randomizing function, whereby different copies of the interpreter and library are unique for each publisher, and therefore assist in obfuscation of the operation of the interpreter.

14. The method of claim 9 further including reordering of an address table used by the interpreter for accessing the library by using a initialization vector generated from publisher information as a seed for a randomizing function, and using a lookup table to translate the byte codes from the compiler to match the reordering, whereby the byte code values are unique for different publishers and therefore assist in obfuscation of an operation of the interpreter.

15. The method of claim 9 further including modifying constants generated by the compiler by applying a reversible mathematical operation to the constants, and providing reversible mathematical operation to reverse the modification of the constants within the interpreter, thereby assisting in the obfuscation of the operation of the interpreter.

16. The method of claim 15 wherein the reversible mathematical operation is an exclusive OR operation on an initialization vector generated from publisher information, and wherein the initialization vector is stored with the interpreter so that it can be utilized to reverse the modification of the constant during interpreter execution.

17. A method for providing anti-piracy protection for a software application, wherein the software application is written in a standard computer language and compiled into a standard instruction set, comprising:

selecting portions of code from the application to be obscured;

processing the selected portions of application source code with a software tool to generate code comprising a non-standard instruction set, and replacing the selected portions of code with the generated code, therein increasing difficulty of understanding the execution flow of the selected portions of the application; and

providing a software tool for processing the selected portions of application source code on a server, and providing the software tool in the form of a byte code compiler and an interpreter to interpret byte codes generated by the byte code compiler at run-time.

18. The method of claim 17 further including providing a library of routines, wherein the interpreter utilizes the library of routines to assist in interpreting the byte codes.

19. The method of claim 18 further including reordering of the library of routines by using an initialization vector generated from publisher information as a seed for a randomizing function, whereby different copies of the interpreter and library are unique for each publisher, and therefore assist in obfuscation of an operation of the interpreter.

20. The method of claim 18 further including reordering of an address table used by the interpreter for accessing the library routines by using a initialization vector generated from publisher information as a seed for a randomizing function, and using a lookup table to translate the byte codes from the compiler to match the reordering, whereby the byte code values are unique for different publishers and therefore assist in obfuscation of an operation of the interpreter.

21. The method of claim 17 further including incorporating in the server application an anti-piracy protection wrapping feature to wrap the application to be protected wherein other anti-piracy protection methods are applied to the application in addition to byte code obfuscation.

22. The method of claim 17 further including encrypting the byte codes generated by the byte code compiler using a product private key wherein the byte codes can only be decrypted and function properly using a decryption function included in the interpreter using a product public key.

23. The method of claim 17 further including randomizing the byte codes generated by the byte code compiler using a reversible mathematical function, and providing a function within the interpreter to reverse the randomization of the byte codes, wherein the byte codes are different for each copy of the application.

24. The method of claim 17 further including modifying constants generated by the compiler by applying a reversible mathematical operation to the constants, and providing the reversible mathematical operation to reverse the modification of the constants within the interpreter, thereby assisting in obfuscation of an operation of the interpreter.

25. The method of claim 24 wherein the reversible mathematical operation is an exclusive OR operation on an initialization vector generated from publisher information, and wherein the initialization vector is stored with the interpreter so that it can be utilized to reverse the modification of the constant during interpreter execution.

26. A method for providing anti-piracy protection for a software application, wherein the software application is written in a standard computer language and compiled into a standard instruction set, comprising:

selecting portions of code from the application to be obscured;

processing the selected portions of application source code with a software tool to generate code comprising a non-standard instruction set, therein increasing difficulty of understanding the execution flow of the selected portions of the application; and

providing the software tool in the form of a byte code compiler, and providing an interpreter to execute the byte codes generated by the byte code compiler at run time.

27. The method of claim 26 further including providing a library of routines, wherein the interpreter utilizes the library of routines to assist in interpreting the byte codes.

28. The method of claim 27 further including reordering of library routines by using an initialization vector generated from publisher information as a seed for a randomizing function, whereby different copies of the interpreter and library are unique for each publisher, and therefore assist in obfuscation of the operation of the interpreter.

29. The method of claim 27 further including reordering of a address table used by the interpreter for accessing the library routines by using a initialization vector generated from publisher information as a seed for a randomizing function, and using a lookup table to translate the byte codes from the compiler to match the reordering, whereby the byte code values are unique for different publishers and therefore assist in obfuscation of the operation of the interpreter.

30. The method of claim 26 further including providing the software tool as part of an anti-piracy protection wrapping toolset

31. The method of claim 26 further including encrypting the byte codes generated by the byte code compiler using a product private key wherein the byte codes can only be decrypted and function properly using a decryption function included in the interpreter using a product public key.

32. The method of claim 26 further including randomizing the byte codes generated by the byte code compiler using a reversible mathematical function, and providing the reversible mathematical function within the interpreter to reverse the randomization of the byte codes, wherein the byte codes are different for each copy of the application.

33. The method of claim 26 further including modifying constants generated by the compiler by applying a reversible mathematical operation to the constants, and providing the reversible mathematical function to reverse the modification of the constants within the interpreter, thereby assisting in the obfuscation of the operation of the interpreter.

34. The method of claim 33 wherein the reversible mathematical operation is an exclusive OR operation on an initialization vector generated from publisher information, and wherein the initialization vector is stored with the interpreter so that the vector can be utilized to reverse the modification of the constant during interpreter execution.