Abstract: A method and system for watermarking software is disclosed. In one aspect, the method and system include providing an input sequence and storing a watermark in the state of a software object as the software object is being run with the input sequence. In another aspect, the method and system verify the integrity or origin of a program by watermarking the program. The watermark is stored as described above. In this aspect, the method and system also include building a recognizer concurrently with the input sequence and the watermark. The recognizer can extract the watermark from other dynamically allocated data and is kept separately from the program. The recognizer is adapted to check for a number. In another aspect, the software is watermarked by embedding a watermark in a static string and applying an obfuscation technique to convert the static string into executable code. In another aspect, the watermark is chosen from a class of graphs having a plurality of members and applied to the software.

Abstract: A method and system for watermarking software is disclosed. In one aspect, the method and system include providing an input sequence and storing a watermark in the state of a software object as the software object is being run with the input sequence. In another aspect, the method and system verify the integrity or origin of a program by watermarking the program. The watermark is stored as described above. In this aspect, the method and system also include building a recognizer concurrently with the input sequence and the watermark. The recognizer can extract the watermark from other dynamically allocated data and is kept separately from the program. The recognizer is adapted to check for a number. In another aspect, the software is watermarked by embedding a watermark in a static string and applying an obfuscation technique to convert the static string into executable code. In another aspect, the watermark is chosen from a class of graphs having a plurality of members and applied to the software.

Abstract: In the tamperforoofing of watermarked computer programs, a constant in the computer program is replaced with a function call. The function call has one or more arguments that point to a data structure built by said program. The replacement can involve referencing a data sub-structure defined by one or more of its arguments, and decoding the constant from the sub-structure.

Abstract: The present invention provides obfuscation techniques for enhancing software security. In one embodiment, a method for obfuscation techniques for enhancing software security includes selecting a subset of code (e.g., compiled source code of an application) to obfuscate, and obfuscating the selected subset of the code. The obfuscating includes applying an obfuscating transformation to the selected subset of the code. The transformed code can be weakly equivalent to the untransformed code. The applied transformation can be selected based on a desired level of security (e.g., resistance to reverse engineering). The applied transformation can include a control transformation that can be creating using opaque constructs, which can be constructed using aliasing and concurrency techniques. Accordingly, the code can be obfuscated for enhanced software security based on a desired level of obfuscation (e.g., based on a desired potency, resilience, and cost).