数字水印的安全性研究综述

Survey of digital watermark security

给出了数字水印安全性研究的发展全貌.通过对现有安全性概念的分析,区分了密码学和数字水印,同时区分了安全性和鲁棒性的概念.讨论了水印安全性分析的一般框架和数学理论以及它们的优缺点.借助密码分析学中用于安全性分析的概念,对水印的安全性分析进行了讨论.攻击的目的是为了发现嵌入水印所使用的秘密钥,使用信息论作为工具进行分析.Shannon的互信息和Fisher信息矩阵可以度量信息的泄露,因而可以定义水印的安全等级.复杂程度也可用来描述水印安全性和定义安全等级.在分析了现有结论后,给出认为值得进一步研究水印安全性的方向.

An overview of the security issues in digital watermarking is provided. After explaining the present concepts of the security, the differences between digital watermarking and cryptography are given, and the concept of security and robustness are discriminated. The general framework and mathematical theory of security analysis are introduced, and their advantages and deficits are discussed. Moreover, a comparison with cryptanalysis is presented in parallel with the discussion. The attack＇s goal is to discover the private key used to embed the watermark. Tools from information theory are used. Shannon＇s mutual information and Fisher＇s information matrix can measure this leakage of information. Thus, the security level can be defined. These also can be estimated by the complexity. Finally, after analyzing the present conclusions, some research directions are put forward for further analysis.