A fragile software watermarking algorithm for content authentication

A new fragile blind watermarking algorithm for content authentication is proposed in this paper. Firstly, the program (cover work) is divided into segments according to the three basic program control structures (sequence, branch and loop). Secondly, the frangibility of watermark is used to mark the variation of the code line, which achieved through using a hash function and generalized character sums. The process of authentication is completed through two phases. The first phase is segment authentication. The program can be passed successfully only if each segment authentication can be passed. The second phase is line authentication, which will be taken only if one of the segment authentications is not passed. The tampered line will be located at this phase. Not only can the algorithm be used to the content authentication, but also it can be applied in software tamper-proofing,control structure authentication and software configuration management etc.