Software self-defense systems and methods

• US 7,823,135 B2
• Filed: 04/07/2005
• Issued: 10/26/2010
• Est. Priority Date: 07/29/1999
• Status: Active Grant

• Current Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Original Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Inventors: Matheson, Lesley R., Maheshwari, Umesh, Horning, James J., Sibert, W. Olin, Wright, Andrew K., Tarjan, Robert E., Horne, William G., Owicki, Susan
• Primary Examiner(s): Zhen; Wei Y
• Assistant Examiner(s): Wu; Junchun
• Application Number:
  US11/102,306
• Publication Number:
  US 20050183072A1
• Time in Patent Office: 2,028 Days
• Field of Search: 713187-190, 717126-127
• US Class Current: 717/127
• CPC Class Codes: G06F 11/3612 by runtime analysis performance monitoring G06F11/3466
• CPC Class Codes: G06F 11/362 Software debugging
• 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 21/125 by manipulating the program code, e.g. source code, compiled code, interpreted code, machine code
• CPC Class Codes: G06F 21/14 against software analysis or reverse engineering, e.g. by obfuscation

Abstract

Systems and methods are disclosed for protecting a computer program from unauthorized analysis and modification. Obfuscation transformations can be applied to the computer program'"'"'s local structure, control graph, and/or data structure to render the program more difficult to understand and/or modify. Tamper-resistance mechanisms can be incorporated into the computer program to detect attempts to tamper with the program'"'"'s operation. Once an attempt to tamper with the computer program is detected, the computer program reports it to an external agent, ceases normal operation, and/or reverses any modifications made by the attempted tampering. The computer program can also be watermarked to facilitate identification of its owner. The obfuscation, tamper-resistance, and watermarking transformations can be applied to the computer program'"'"'s source code, object code, or executable image.

Claims

1. A method for obfuscating a computer program, the computer program containing a sequence of programming instructions, the method including:

incorporating one or more programming constructs into the computer program, the programming constructs being operable to designate one or more memory locations for storage of data, and wherein the one or more memory locations are logically located between a first memory location and a second memory location, the first memory location containing at least part of a programming instruction from the sequence of programming instructions, and the second memory location containing at least part of a programming instruction from the sequence of programming instructions;

incorporating one or more memory allocation statements into the computer program, the memory allocation statements being operable to allocate memory for storage of data, and wherein at least a portion of the memory allocated for storage of data includes one or more of the memory locations designated by the programming constructs for storage of data;

storing data within the memory allocated for storage of data,

whereby the distinction between an area of memory primarily containing programming instructions and an area of memory primarily containing data is at least somewhat obscured.

2. A method as in claim 1, in which the data include one or more programming instructions.

3. A method as in claim 1, further including:

deallocating the memory allocated for storage of data; and

reallocating the memory allocated for storage of data.

4. A method as in claim 1, whereby the computer program is rendered more resistant to reverse engineering, decompilation, or deobfuscation.

5. A method as in claim 1, in which the data include data for watermarking the computer program.

6. A method as in claim 1, in which the data include rules and/or controls for governing use or operation of the computer program.