信息隐藏技术-第六章-数字指纹.ppt
第六章 数字指纹,第五章 内容回顾,2023/9/5,2,数字视频水印基础鲁棒视频水印算法脆弱视频水印算法视频水印几个特殊问题与方法,第六章 主要内容,2023/9/5,3,数字指纹概述多用户合谋攻击典型数字指纹数字指纹安全协议,What is digital fingerprinting,2023/9/5,4,Human fingerprintSimilar with human fingerprintA group of special watermarks embedded into digital media data different from each other/every one is unique;can be used to identify any one copy;can be used to trace pirate and traitors.,Digital fingerprinting,2023/9/5,5,Design goals,2023/9/5,6,Catch many The goal in this design scenario is to capture as many colluders as possible,though possibly at a cost of accusing more innocent users.For this desired goal,the set of performance criteria consists of the expected fraction of colluders that are successfully captured and the expected fraction of innocent users that are falsely placed under suspicion.,数字指纹的发展历史,2023/9/5,7,英国内阁秘密文件泄密事件 1981年，英国内阁秘密文件的图片被翻印在报纸上登出。传闻事先玛格丽特.撒切尔夫人给每位部长分发了可唯一鉴别的文件副本。每份副本有着不同字间距，用于确定收件人的身份信息，用这种方法查出了泄密者。,数字指纹的发展历史,2023/9/5,8,关于数字指纹技术的最早论文是在1983 年发表的题为Fingerprinting的文章，介绍了指纹的思想和一些术语，并提出了基于假设校验的统计指纹。1994年Benny Chor，Amos Fiat，Moni Naor发表文章“Tracing traitors”。文中提出了三种方案来对抗多个不诚实用户的合谋攻击，其思想成为后来许多抗合谋数字指纹方案的基础。,数字指纹的发展历史,2023/9/5,9,C.Boneh和H.Shaw于1995年提出了一个清晰的抗合谋攻击的编码方案，称为C-安全编码（C-secure code）的数字指纹经典方案。该方案对嵌入条件作了假设，其编码方法与使用的数据嵌入算法无关。随后出现了用于叛逆者跟踪和数字取证的数字指纹技术，并得到了广泛的研究。非对称指纹，匿名指纹；汉明码，BIBD，高斯分布指纹，Micosoft Research:a dual watermark-fingerprint.,数字指纹的主要问题,2023/9/5,10,Works well without any attackA common watermark attacks/single-copy attacksMulti-copy attacks/Collusion attacks Colluders use their copies to produce a new copy employing various ways.They decrease the risk of being captured from the new copy possibly.合谋攻击/共谋攻击。,第六章 主要内容,2023/9/5,11,数字指纹概述多用户合谋攻击典型数字指纹数字指纹安全协议,多用户合谋攻击,2023/9/5,12,Linear collusion and non-linear collusion,Users,Distributed copies,Digitalfingerprints,New image copy,线性合谋,2023/9/5,13,Linear collusion,非线性合谋,2023/9/5,14,1）随机选择拷贝方式：2）随机选择值方式：3）最小值方式：4）最大值方式：5）中值方式：6）最小值-最大值方式：7）最小值-最大值-中值：8）随机最小值-最大值：,非线性合谋攻击,2023/9/5,15,1 H.Vicky Zhao,Min Wu,Z.Jane Wang,et al.Forensic analysis of nonlinear collusion attacks for multimedia fingerprinting,IEEE Transactions on image processing,2005.5,Vol.14,No.5,646-661.,两个重要指标,2023/9/5,16,The probability of a false negative PfnThe probability of a false positive Pfp Pfp10-6,Pfn10-3.Different concerns arise under different situations,however the fingerprinting system must be designed according to appropriate performance criteria.,Design goals,2023/9/5,17,Catch one For this desired goal,the set of performance criteria consists of the probability of a false positive and the probability of a false negative.From the detectors point of view,a detection approach fails when either the detector fails to identify any of the colluders(a false negative)or the detector falsely indicates that an innocent user is a relevant when providing evidence in a court of law.,Design goals,2023/9/5,18,Catch all In this design scenario,the fingerprints are designed to maximize the probability of capturing of innocents being falsely accused.This arises when the trustworthiness of the information recipients is of such great concern that all users involved in the information leak need to be identified.This set of performance criteria consists of measuring the probability of capturing all colluders and an efficiency rate,which describes the expected amount of falsely accused innocents per colluder.,非线性合谋攻击,2023/9/5,19,Particular attacks,第六章 主要内容,2023/9/5,20,数字指纹概述多用户合谋攻击典型数字指纹数字指纹安全协议,典型数字指纹方法,2023/9/5,21,高斯分布指纹BIBD码指纹A dual watermark-fingerprint,高斯分布指纹,2023/9/5,22,Use independent normally distributed random values as fingerprintsNon-blind detection,攻击模型,2023/9/5,23,Average attack,非盲检测,2023/9/5,24,Non-blind detection,Maximum detector,2023/9/5,25,Catch one,Maximum detector,2023/9/5,26,Catch one,Maximum detector,2023/9/5,27,表1 非盲最大值检测器Lmin和h设计值,Thresholding detector,2023/9/5,28,Catch many,Thresholding detector,2023/9/5,29,表2 非盲阈值检测器Lmin和h设计值,BIBD码指纹,2023/9/5,30,Anti-collusion codes,ACCs,抗合谋码 Wade Trappe,Min Wu,Z.Jane Wang,et al.Anti-collusion Fingerprinting for MultimediaJ,IEEE Transactions on Signal Processing,2003,Vol.51,No.4,1069-1087.,BIBD码指纹,2023/9/5,31,当合谋发生时，各拷贝之间信号不同部分将可能被衰减或干扰，而相同部分则没有这个问题。因此，构造抵抗合谋的编码的基本思想是这样的，如果两份拷贝的指纹水印它们具有相同的成份，那么这一相同成份就不会被合谋操作衰减，如果在所有用户拷贝中，任何两个拷贝组合都具有唯一的相同成份，那么该指纹水印系统就可识别任意两个用户的合谋。以此类推，如果任何K个拷贝组合都具有唯一的相同成份，那么该指纹水印系统就可识别任意K个用户的合谋。满足这样性质的码被Wade Trappe、Wu Min等称为抗合谋码（Anti-collusion codes,ACCs）。,BIBD码指纹,2023/9/5,32,Wade Trappe、Wu Min等利用组合数学中的区组设计理论来设计抗合谋码。区组设计理论已被应用于纠错码的构造和统计实验的设计。他们提出利用BIBD来构造抗合谋码，BIBD（Balanced incomplete block design），即均衡不完全区组设计。,BIBD抗合谋码例子,2023/9/5,33,A dual watermark-fingerprint,2023/9/5,34,Microsoft Research的Darko Kirovski等提出了一种新的思路来设计“双重”指纹水印系统（A dual watermark-fingerprint system），这里的“双重”是，水印用以指明许可外，系统还可进行指纹追踪。该方法与前面讨论的不同拷贝嵌入不同水印的思路不同，它对分发给用户的所有拷贝，都嵌入相同的水印，但分发给每个用户的检测密钥是各不相同的，具有唯一性，以此作为数字指纹来识别用户。Darko Kirovski,Henrique Malvar and Yacov Yacobi,A dual watermark-fingerprint system.IEEE Multimedia,2004,59-73,A dual watermark-fingerprint,2023/9/5,35,第六章 主要内容,2023/9/5,36,数字指纹概述多用户合谋攻击典型数字指纹数字指纹安全协议,数字指纹安全协议,2023/9/5,37,对称指纹技术的安全漏洞 指纹技术是通过发行商验证非法分发拷贝的原始购买者来防止非法拷贝。但是，对于对称指纹方案来说，购买者和发行商都能识别出嵌入指纹的拷贝。因此，发行商在某地发现了非法拷贝的时候，发行商并没有证据证明分发这个非法拷贝的人就是某个用户，而不是发行商本人。为了解决这个问题，Pfitzmann和Schunter提出了非对称指纹。,非对称数字指纹,2023/9/5,38,方案由4个协议组成 key-gen,fing,identify,dispute.只有买方知道具有指纹的数据 B.Pfitzmann and M.Schunter,“Asymmetric fingerprinting”,in Advances in Cryptology,Proceedings of EUROCRYPT96,vol.1070 of Lecture Notes in Computer Science,1996,pp.84-95,匿名数字指纹,2023/9/5,39,买方能以匿名的形式购买拷贝，但是如果他们非法重新发行这种信息，仍然能被识别出来 B.Pfitzmann and M.Waidner,Anonymous fingerprinting,”,in Advances in Cryptology,Proceedings of EUROCRYPT97,vol.1233 of Lecture Notes in Computer Science,1997,pp.88-102主要思想：与密码学中的安全协议结合,
