过分伤痛Abstract. We have developed the first hardware and software (intellectual property) metering scheme that enables reliable low overhead proofs for the number of manufactured parts and copied programs. The key idea is to make each design slightly different d
the main flow of the program when a special function is invoked from command or highly unlikely data input. Our preferred mode is to use don’t care conditions in the control flow of the program to enter the ID module. Program obfuscation can be used to protect the module isolation and altering against attacks. The module may have either dynamic data structures as information carrier or can just create a particular output sequence.
In addition to mechanism differences, there two other key differences between the schemes discussed in [8] and the one just proposed. The first is that our goal is different:instead of watermarking, we want only creation of distinct copies. This condition makes not only the software mutation task easier, but also induces low size and/or performance overhead. The second difference is even more important. Our primary technical goal is to enable rapid ID authentication for a software component/product. Therefore, the idea is to create versions that rapidly create different IDs that can be verified against database of produced copies. Note that our technique can be used, with straightforward modification,also for software watermarking. The final alternative to software metering which we dis-cuss is conceptually most complex, but also potentially most rewarding. The idea is to alter software in such a way that each output produces by different version of the software which differs from each other. This can be easily achieved by postprocessing the final out-put within the software. More interestingly, it can be demonstrated that in many cases one can systematically alter software in such a way that the functionality is essentially pre-served. Typical example include word processing, large scale optimization and computer-aided design packages.
