基于可再分发抗合谋编码的低失真水印方案

Low‑Distortion Watermark Scheme Based on Redistributable Anti‑collusion Coding

在大数据的时代背景下,数据潜在的价值使其成为重要的财富之一。数据的非法篡改、修正和非法分发给追踪数据的泄密源头带来巨大挑战。数字指纹技术可应用在数据泄密溯源领域,即在数据中嵌入一串能够唯一标识用户信息的序列,当数据发生泄密后,提取其中蕴含的数字指纹,追踪到泄密的叛逆者。多个用户对数据合谋攻击并泄密数据,从而毁坏其中嵌入的指纹信息达到逃脱追责的目的,抗合谋编码能够解决此问题。针对现有的数字指纹编码无法满足数据再分发需求、数字指纹嵌入造成较大数据失真的问题,本文使用BIBD(Balanced incomplete block design)作为外码,码字扩展后的C码作为内码,构建一种可再分发的抗合谋指纹编码RD‑ACC(Redistributable anti‑collusion fingerprint coding)。在此基础上,提出一种基于多目标优化的数据库指纹算法,能够在较小的数据库失真情况下保证数字指纹较高的鲁棒性,提取出的RD‑ACC能够有效抵抗组内、组间多用户合谋攻击。实验结果表明,该算法能够在较小的数据失真下实现数据的再分发操作,并且能抵抗合谋攻击进行泄密溯源。

In the era of big data,the potential value of data makes it one of the important assets.The illegal tampering,correction and illegal distribution of data bring great challenges to tracing the source of data leakage.Digital fingerprint technology can be applied in the field of traceability of data leakage,that is,a sequence of unique identification of user information is embedded in the data.Multiple users conspire to attack data and leak data,thereby destroying the fingerprint information embedded in it to escape accountability.Anti-collusion coding can solve this problem.Aiming at the problems that the existing digital fingerprint encoding cannot meet the data redistribution requirements and the digital fingerprint embedding causes large data distortion,this paper uses the balanced incomplete block design(BIBD)as the outer code and the C code after codeword expansion as the inner code to construct a redistribution anti-collusion fingerprint coding(RD-ACC).On this basis,a database fingerprint algorithm based on multi-objective optimization is proposed to ensure high robustness of digital fingerprints under the condition of small database distortion.The extracted RD-ACC can effectively resist intra-group and inter-group multi-user collusion attack.Experimental results show that the algorithm can realize the data redistribution operation with less data distortion,and resist the collusion attack to trace the source of leaks.