针对动态图编码时间复杂度较高的问题,提出一种四进制编码方案,利用空间换时间的思想,通过增加两个专门用来编码系数的指针域,在空间复杂度不变的情况下,降低构造水印图的时间复杂度。同时借鉴计算机网络和数据通信的差错检验原理,提出一种基于循环冗余校验的动态图软件水印防窜改技术,实现了水印图的动态验证。实验表明,该方案提高了水印数据率,增强了水印抗攻击性,并使之具有一定的纠错能力。
This paper proposed a quaternary-encoding schema towards the problem of the high time complexity of dynamic graph encoding, which could decrease the graph constructing time complexity by the means of creating two special fields for encoding coefficient with the thought of space-for-time while the space complexity remained unchanged. Meanwhile, adopting from the principle on the computer network and data communication, proposed a dynamic graph software watermarking tamperproofing technology based on the CRC, which implemented the watermarking graph dynamic verifying. Experiment shows that this schema increases the watermarking data rate and enhances the watermarking resistance and has certain capability of error correction.