抗拼接攻击的矢量瓦片数据水印算法

Watermarking Algorithm for Vector Tiled Data against Mosaic Attack

网络环境下矢量瓦片数据应用广泛,引发多用户、多线程的非法爬取等安全问题。该文针对网络环境矢量瓦片数据版权保护和用户追溯的需求,提出了一种抗拼接攻击、鲁棒性强的矢量瓦片水印算法。首先,在水印信息生成阶段对两段编码进行设计,在保证区分度的同时,提供尽可能多的用户编码;其次,在水印嵌入和检测阶段,改进了经典的量化索引调制方法,根据矢量瓦片的精度划分更多数量的区间,以提高水印容量。实验结果表明,该文提出的矢量瓦片水印算法能够保证数据的可用性,并且对增加、删除、更新以及多用户的拼接攻击均具有较好的鲁棒性,实现了矢量瓦片的版权保护和用户追溯功能。

While vector tiled data have been widely used in the Internet and Web,the security issues such as illegal crawling or copy need to be solved urgently.Aiming at the copyright protection and user tracking for vector tiled data in network environment,a robust watermarking algorithm designed to resist mosaic attack is proposed in this paper.In the proposed algorithm,watermark is generated by two segments,and the watermark generation algorithm can provide as many codes as possible while ensuring the discriminations between groups and users.Moreover,in the watermark embedding and extraction stage,the classical quantization index modulation method is improved by dividing a certain number of intervals according to the data precision.Thereby the watermark capacity is increased largely.The experiments have been conducted to verify the proposed algorithm,and the results show that this algorithm ensures the availability and the precision of the data.Besides,its superior robustness against data addition,deletion,update and multi-user mosaic attack has also been proved by the experiments,meaning the proposed method is applicable for copyright protection and user tracking for vector tiled data.