New software watermarking algorithm based on equation
一种新的方程式软件水印算法*

For the matter that equation re-sorting algorithm were easily attacked by the random re-sequencing technology, this paper proposed the software watermark algorithm based on Chinese remainder theorem, and introduced the watermark authentication center.The algorithm decomposed the watermark by the Chinese remainder theorem, and made related operations between the decomposed sequence and the equation coefficients sequence, made the watermark associated with the coefficient of the equation. The sequence obtained, the selected divisor sequence and the multiple were further processed to generate a key, which was only belonged to the copyright ow-ner and kept in secret condition. When checking the copyright, the copyright owner could extract the correct watermark only by key decryption and relative operations, and the watermark extraction achieved blind detection completely, without adding any code into the program. The experiment results show that the algorithm is robust, as well as the code length and speed of program will not be affected, and its performance is better than the equation re-sorting algorithm.