Research On A Software Watermarking Algorithm

Software watermarking is a new method used to protect the copyright of software. Unlike traditional software-protecting methods dependent only on encryption techniques, software watermarking embeds certain secret information into host software codes and the embedded secret information can be extracted from the software when needed.Software watermark can be divided into static software watermark and dynamic software watermark. Static software watermark is stored in the executive codes while dynamic software watermark in the executive state, it is easier to build and extract static software watermark, and static software watermark is also more frangible to dewatermarking attacks comparing with dynamic software watermark, in other words, dynamic software is more robust than static software watermark.This paper classifies existing algorithms for software watermarking and proposes a new dynamic watermarking algorithm including embedding watermark and extracting watermark and implements a prototype. In this algorithm, the product of two huge primes is the secret information, which is further converted into n natural numbers and then encoded into planted plane cubic tree structures which are embedded into the software codes as software watermark. Debugging software is needed in the recognizing phase, it is used to watch the execution state, when all planted plane cubic tree structures are detected, they will be decoded into n natural numbers, and the original product of two prime numbers will be got through Chinese Remaining Theory. At last, future work and conclusion are given.