中文摘要：

简单介绍了动态图水印的特征,概括了典型的PPCT的编码特征和纠错属性,分析了分别将PPCT与排列图和k-基数相结合的编码方案,提出一种改进的PPCT防篡改水印方案。该方案在不改变PPCT结构的前提下,引入基数编码提高了水印的数据率;利用防篡改技术弥补了PPCT纠错属性的局限性,实现了水印的双重防篡改功能;采用水印的冗余嵌入实现了水印的容错提取,增强了水印的鲁棒性。

英文摘要：

In this paper we briefly introduced the features of ideal dynamic graph-based watermarks,generalized the encoding characteristics and the error-correcting properties of typical PPCTs,and then analysed the encoding schemes which combines PPCT with permutation graph and k-radix encoding respectively,finally we proposed an improved tamper-proofing watermarking scheme based on PPCTs.The scheme improves the data rate of watermarking by introducing radix encoding without modifying the structures of PPCTs.It utilizes tamper-proofing technology to make up the limitation of PPCTs＇error-correcting properties,so as to have realized dual tamper-proofing functions of the watermarking.The scheme also adopts redundancy embedding on watermarking to have realised watermarking error-tolerant extraction,and thus the robustness of watermarks is enhanced.