I. J. Cox and J. P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications, vol. 16, pp. 587--593, May 1998.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....watermarks are not secure against exhaustive search for the embedded sequence. Eigenvector watermarks can be much more secure, if the eigenvector belongs to an eigenvalue of G with a large geometric multiplicity. However, attacks like the sensitivity attack described by Cox and Linnartz in [4] might be successful if good objective quality measurements without reference to the original signal are known. Instead of removing an embedded watermark, an attacker can try to confuse the public watermark detector by adding another signal z with the property Clz = oZ , where 0. The ....

I.J. Cox and J.-P. Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16:587 593, May 1998.

....I ) whenever images I and I are dissimilar; 2. W(K, I ) is strongly correlatedwith W(K, I ) whenever I and I are similar (I is the image I after an attack comprising of a rotation, scale, and grayscale modifications) 3. W(K, I ) is uncorrelated with W(K , I ) for KvsK . Linnartz and Cox [5, 6] proposed simila requirements for watermarking digital video disks (DVD) The requirements 1 3 could be satisfied provided we have a robust image digest function H (visual hash function) that returns the same N bits (or almost the same N bits) for all images I that underwent a combination of a ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks", preprint, 1998.

....watermarks are not secure against exhaustive search for the embedded sequence. Eigenvector watermarks can be much more secure, if the eigenvector belongs to an eigenvalue of # with a large geometric multiplicity. However, attacks like the sensitivity attack described by Cox and Linnartz in [4] might be successful if good objective quality measurements without reference to the original signal are known. Instead of removing an embedded watermark, an attacker can try to confuse the public watermark detector by adding another signal z with the property #z # # z,where #. The ....

I.J. Cox and J.-P. Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16:587--593, May 1998.

....and most watermarks can be easily defeated even by simple image manipulations. This reduces the practical usefulness of such watermarks, and leads to the question of whether more robust schemes can be developed. We describe new watermarking algorithms designed to resist a wide variety of attacks [11, 12, 13]. These include both common image processing distortions, such as lossy compression, rescaling, and cropping; and malicious attacks, including watermark distorting software such as StirMark and unZign [14, 15] For embedding and detecting one or more bits in images, we use a standard ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications, vol. 16, no. 4, May 1998.

....illicit copies were made. In another example, the embedded signal could either enable or disable copying by some duplication device that checks the embedded signal before proceeding with duplication. Such a system has been proposed for allowing a copy once feature in digital video disc recorders [2]. Alternatively, a standards compliant player could check the watermark before deciding whether or not to play the disc [3] Other applications include automated monitoring of airplay of advertisements on commercial radio broadcasts. Advertisers can embed a digital watermark within their ads and ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun., vol. 16, pp. 587--593, May 1998.

....assert (we believe rightly) to the contrary: that some watermarks should be readily perceptible. Copy protection applications require that a watermark can be read by anyone, even by potential copyright pirates, but nonetheless only the sender should be able to embed and erase the watermark [Cox and Linnartz, 1998]. Other authors concur with this requirement of visibility: By watermarks we mean marks that are readily detectable, even by a casual user, such as a logo or banner that appears to be lightly printed over eachpageofadocument [Kaplan, 1996] The Oxford English Dictionary defines ....

Cox, I. and Linnartz, J.-P. (1998). Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16(4):587--593.

....communications (including steganography) 3. ATTACK CATEGORIES Before introducing the various watermarking applications scenarios it might be useful to classify all possible types of attacks on the basis of their effect on the watermark and the way the watermark is interpreted by the detector [12] [14] In this way, four broad categories can be formed [15] Removal attacks: This category includes attacks that aim at removing the watermark without degrading the perceptual quality of the product. These can be unintentional attacks that occur during common processing operations by the ....

I.J. Cox and J.P. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal of Selected Areas of Communications, vol. 16, no. 4, May 1998.

....used in cryptography. There are the brute force attacks which aim at finding secret information through an exhaustive search. Since many watermarking schemes use a secret key it is very important to use keys with a secure length. Another attack in this category is the so called Oracle attack [54,14] which can be used to create a non watermarked image when a watermark detector device is available. 2.4 Protocol attacks The protocol attacks aim at attacking the concept of the watermarking application. The first protocol attack was proposed by Craver et al. [16] They introduce the framework of ....

I. J. Cox and J.-P. M. G. Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16(4):587-- 593, May 1998.

....information by a certification authority. Attacks at Other Levels. There are a number of attacks that are directed to the way the watermark is manipulated. For instance, it is possible to circumvent copy control mechanisms discussed below by superscrambling data so that the watermark is lost [9] or to deceive web crawlers searching for certain watermarks by creating a presentation layer that alters they way data are ordered. The latter is sometimes called mosaic attack [6] 5. APPLICATIONS In this section we discuss some of the scenarios where watermarking is being already used as ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks, " IEEE J. Select. Areas Commun, vol. 16, pp. 587--593, May 1998.

....whether or not a given image is watermarked but the detector itself should not enable a pirate to remove the watermark from the image or recover the watermarking key wired in the black box. Such a detector would find important applications in control of illegal copying of Digital Video Disks DVDs [14,15]. Kalker recently established [16,17] that if the watermark detector is a linear correlator it is always possible to remove the watermark from an image if the black box watermark detector is available. Linnartz et al. 14,18] present an iterative method for removing the watermark based on the ....

....most important arguments for using keydependent basis functions is the fact that this concept may enable construction of a secure public watermark detector that is implemented as a black box in a tamper proof hardware. Such watermark detectors find important applications in copy control of DVD [14,15]. The box accepts integer matrices on its input and outputs one bit of information. It is assumed that the complete design of the detector and the corresponding watermarking scheme are known except a secret key, and that an attacker has one watermarked image at his disposal. The latest attacks on ....

[Article contains additional citation context not shown here]

I.J. Cox and Jean-Paul M.G. Linnartz, "Some general methods for tampering with watermarks", preprint, 1998.

....frame I. More formally, W(K, I ) is uncorrelated with W(K, I ) whenever I and I are dissimilar, W(K, I ) is strongly correlated with W(K, I ) whenever I and I are similar (I is the frame I after an attack or watermarking) and W(K, I ) is uncorrelated with W(K , I ) for KK . Linnartz and Cox [4, 5] proposed similar requirements for watermarking DVDs. This paper presents a solution to this problem. The method presented here is an extension and improvement of the robust bit extraction method proposed in [3] In Section 2, we describe a method for extracting N bits from image blocks so that ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks", preprint, 1998.

....on watermarking systems is their robustness against a variety of unintentional or malicious attacks including lowpass highpass distortions, compression, noise corruption, geometric distortions. An overview of possible attacks and the limitations of many current approaches is given in [5] 30] [35]. The foundation for performance evaluation of the majority of watermarking methods has been mostly experimental usually without any theoretical justi cation of their eciency. Only few researchers have attempted to statistically analyze the performance of image watermarking schemes in terms of ....

I. Cox, J. Linnartz, Some general methods for tampering with watermarks, IEEE Journal of Selected Areas of Communications 16 (4).

....illicit copies were made. In another example, the embedded signal could either enable or disable copying by some duplication device that checks the embedded signal before proceeding with duplication. Such a system has been proposed for allowing a copy once feature in digital video disc recorders [2]. Alternatively, a standards compliant player could check the watermark before deciding whether or not to play the disc [3] Other applications include automated monitoring of airplay of advertisements on commercial radio broadcasts. Advertisers can embed a digital watermark within their ads and ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications, vol. 16, pp. 587--593, May 1998.

....resides. Since down sampling by 2 and then upsampling an image introduces minor visual artifacts, this actually indicates a very simple method to remove the watermark embedded by the BlkDCTHF method. E. Robustness to shifting Shifting is another dicult problem for many watermarking algorithms [5], 17] However, in our proposed scheme, the watermark is inserted in the low frequency subband of the original image, which can be viewed as a TABLE III Lena: Similarity measure after filtering Operation Blurring Sharpening Scaling Oil painting BlkDCTHF 5.91 12.94 0.32 4.11 GlbDCT1 24.31 ....

....the shifted image, we pad the empty left margin with pixel value of 128. As shown in Table IV, the similarity drops very close to zero when the image is right shifted by only 3 or 4 pixels, making the watermark indistinguishable from random noise. This is consistent with the results reported in [5], 17] which veri es that these algorithms are very vulnerable to shifting operation. To demonstrate the shift invariant capability of our proposed algorithm, the similarity measures with respect to circular shifting are provided in Fig. 8(a) 9(a) and 10(a) As shown in Fig. 8(a) when a ....

I. J. Cox and J. Linnartz, \Some general methods for tampering with watermarks", IEEE Journal on selected areas in communications, Vol. 16, No. 4, pp. 587-593, May 1998.

....its possible contribution to develop an overall system for copyright protection and content verification. Watermarking has been applied successfully to many multimedia modalities. A large portion of the watermarking literature deals with the copyright protection of still digital images (e.g. [18, 19, 20, 21, 22, 23, 24]) Watermarking algorithms for digital video [25, 26] and digital 3 audio [27, 28, 29] have been developed as well. The proposed watermarking framework is general and abstract and can cover all the above mentioned modalities. The structure of this paper is the following. In the next section we ....

....resistance to product modifications. 3.3 Watermark detection Watermark detection should be performed on any product X, preferably without the use of the original product. Some watermarking techniques use the original product in order to address efficiently some watermark robustness issues (e.g. [20]) However, the use of the original is a big disadvantage when watermarking is used for product monitoring in network distribution or broadcasting. Therefore, we consider detection without resorting to the original product. We proceed to watermark detection, by generating first the watermark ....

I. J. Cox and J. P. Linnartz. Some general methods for tampering with watermarks. IEEE Journal of Selected Areas of Communications, 16(4):587--593, 1998.

.... the averaging of multiple copies of the same original but having differentmarkings[10] When the detector is in the public domain, it is possible to systematically learn about the watermarks from the input output relationship of the detector using many manipulated versions of watermarked image [11]. Watermarks can also be attacked by geometric distortion, including warping, line dropping adding, or in conjunction with moderate lowpass filtering and interpolation [12] 13] but may not be always effective when original image is available to perform registration. In this paper, we propose a ....

I. Cox, J-P. Linnartz, "Some General Methods for Tampering with Watermarks", IEEE JSAC,May, 1998

....counter measures can be found in [3] In [22] the authors present simple and almost invisible image distortions (deletion of a small number of image columns or combination of minor geometric distortions followed by blurring) that render watermarks produced by several methods undetectable. In [23] the authors propose an attack for the so called unrestricted key watermarks assuming that the pirate has access to a watermark detector. The method uses a trial and error procedure to estimate a combination of pixel values that has the largest influence on the detector for the least disturbance ....

I. Cox, J. Linnartz, "Some General Methods for Tampering with Watermarks". IEEE Journal of Selected Areas in Communications, vol 16 no 4, pp 587-593, May 1998.

....detector must also be secure in the sense defined above. At present, it is not clear if a secure black box public detector can be built at all. Recently, attacks on a general class of data embedding techniques that are based on linear correlators have been described [Kal1, Kal2, Linn1, Linn2, Cox1] 2.6 Secure public detector is an even stronger concept for which all details of the detector are publicly known. If such a detector is ever built, it would find tremendous applications since it can be implemented in software rather than tamper proof hardware. It would enable building ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks", preprint, 1998.

....I. More formally, W(K, I ) is uncorrelated with W(K, I ) whenever I and I are dissimilar, W(K, I ) is strongly correlated with W(K, I ) whenever I and I are similar (I is the frame I after an attack or watermarking) and W(K, I ) is uncorrelated with W(K , I ) for K K . Linnartz and Cox [4, 5] proposed similar requirements for watermarking DVDs. This paper presents a solution to this problem. The method presented here is an extension and improvement of the robust bit extraction method proposed in [3] In Section 2, we describe a method for extracting N bits from image blocks so that ....

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks", preprint, 1998.

No context found.

I.J. Cox and J.P.M.G. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Comm., vol. 16. no. 4, pp. 587--593, May 1998.

No context found.

I.J. Cox and J.P.M.G. Linnartz, "Some general methods for tampering with watermarks", IEEE Journ. of Sel. Areas in Comm., Vol. 16. No. 4, May 1998, pp. 587-593.

....DHSG. 3. Challenges As the copy protection system described above and illustrated in Figure 2 is implemented, an array of challenges related to the watermarking technology have arisen. The issue of watermark removal is often addressed in watermarking literature and remains an important concern [5]. There are a number of other issues, some technical and some non technical, which have also come to play an important role. In the remainder of this section we briefly introduce and discuss the following issues: enforcement, system tampering, detector placement within the system, computational ....

Cox, I.J. and Linnartz J-P., Some General Methods for Tampering with Watermarks, IEEE Journal on Selected Areas in Communications, Vol. 16, pp. 587-93, 1998.

....DESIGN ISSUES As the copy protection system described in Section II and illustrated in Fig. 2 is implemented, an array of challenges related to the watermarking technology have arisen. The issue of watermark removal is often addressed in watermarking literature and remains an important concern [9]. There are a number of other issues, some technical and some nontechnical, which have also come to play an important role. In this section we briefly introduce and discuss the following issues: computational cost of the detector and embedder; false positive rates; detector placement within the ....

....Minimally, an MPEG parser and dequantizer have to be present because resources cannot be shared with an MPEG decoder. Second, the watermark detector needs logic to recognize the MPEG data type. This task may become challenging since there are a number of possible circumvention strategies [9], including PC device drivers that intentionally read out disk sectors in random order. Increases in DVD drive data rates will place higher demands on such MPEG detection and watermark detection circuitry. 2) Detector Within the Application: An MPEG decoder that implements the watermark detection ....

[Article contains additional citation context not shown here]

I. J. Cox and J.-P. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun., vol. 16, pp. 587--593, May 1998.

....describe a fully defined and mature system. It must be regarded as a status report from an ongoing discussion. We present our findings from active participation in several forums. Portions of this article have previously appeared as white papers or responses to Calls for Proposals, e.g. 5] [9]. We strongly believe in open, publicly evaluated systems and solutions which have been discussed not only in industrial standardization meetings but also at academic symposia. Some technologies, such as encryption on DVD video discs have been standardized in the Copy Protection Technical Working ....

....features. In particular an integrity mechanism is needed to ensure that the drive and decoder negotiate about the same video data. It would allow the drive to effectuate play control, based on watermarks checked by the decoder. This also prevents the local scrambling or bit inversion attack [9]. Copy Generation Control Having covered the case of content that may never be copied, we must also deal with the much less straightforward implementation of (only) one (generation of) copy allowed. Because of the nature of this Copy Once requirement, information has to be passed along with ....

I.J. Cox and J.P.M.G. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun., vol. 16, pp. 587-593, May 1998.

....paper cannot describe a fully defined and mature system. It must be regarded as a status report from an ongoing discussion. We present our findings from active participation in several fora. Portions of this paper have previously appeared as white papers or responses to Calls for Proposals, e.g. [5 9]. We strongly believe in open, publicly evaluated systems and solutions which have been discussed not only in industrial standardization meetings but also at academic symposia. Some technologies, such as encryption on DVD video discs have been standardized in the Copy Protection Technical Working ....

....features. In particular an integrity mechanism is needed to ensure that the drive and decoder negotiate about the same video data. It would allow the drive to effectuate play control, based on watermarks checked by the decoder. This also prevents the local scrambling or bit inversion attack [9]. 3.2 Copy Generation Control Having covered the case of content that may never be copied, we must also deal with the much less straightforward implementation of (only) one (generation of) copy allowed . Because of the nature of this Copy Once requirement, information has to be passed along ....

I.J. Cox and J.P.M.G. Linnartz, "Some general methods for tampering with watermarks", IEEE Journ. of Sel. Areas in Comm., Vol. 16. No. 4, May 1998, pp. 587-593.

No context found.

I.J. Cox and J.P.M.G. Linnartz, "Some general methods for tampering with watermarks", IEEE Journ. of Sel. Areas in Comm., Vol. 16. No. 4, May 1998, pp. 587-593.

....that this model makes no attempt to deal with the issue of malicious attacks, that is distortions performed by would be pirates with the sole intention of removing the watermark. Distortions of this type, especially those designed using detailed knowledge of the algorithm (for examples, see [CL97, CL98, Kal98, KLvD98, LvD98] are extremely di#cult to analyze, and are not be covered in the present article. However, several malicious attacks are actually pathalogical examples of processes that might otherwise occur with normal processing (for example, see [PAK98] The analysis based on our ....

I.J. Cox and J.-P. M. G. Linnartz. Some general methods for tampering with watermarks. IEEE Trans. on Selected Areas in Communications, 16(4):587--593, 1998.

....attacks. Here the hacker tries to remove the watermark or make it undetectable. This type of attack is critical for many applications, including owner identification, proof of ownership, fingerprinting, and copy control, in which the purpose of the mark is defeated when it cannot be detected [10]. However, it is not a serious problem for authentication or covert communication. Passive attacks. In this case, the hacker is not trying to remove the watermark, but is simply trying to determine whether a mark is present, i.e. is trying to identify a covert communication. Most of the ....

I. J. Cox and J.-P. Linnartz. Some general methods for tampering with watermarks. IEEE Trans. on Selected Areas of Communications, 16(4):587--593, 1998.

....DHSG. 4. CHALLENGES As the copy protection system described above and illustrated in Figure 2 is implemented an array of challenges related to the watermarking technology have arisen. The issue of watermark removal is often addressed in watermarking literature and remains an important concern [5]. There are a number of other issues, some technical and some non technical, which have also come to play an important role. In the remainder of this section we briefly introduce and discuss the following issues: enforcement, system tampering, detector placement within the system, computational ....

Cox, I.J. and Linnartz J-P., Some General Methods for Tampering with Watermarks, IEEE Journal on Selected Areas in Communications, Vol. 16, pp. 587-93, 1998.

No context found.

I. J. Cox and J. P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications, vol. 16, pp. 587--593, May 1998.

No context found.

I.J. Cox and J.P.M.G. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun., vol. 16, pp. 587-593, May 1998.

No context found.

I. J. Cox and J.-P. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun., vol. 16, pp. 587--593, May 1998.

No context found.

I. Cox, And J. Linnartz, Some general Methods for Tampering with Watermarks, IEEE Journal on Selected Areas in Communications, 16, 4, May 1998.

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Ingemar Cox and Jean-Paul Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16(4):587--593, May 1998.

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I. Cox and J.-P. Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16(4):587-593, 1998.

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I. J. Cox and J.-P. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun. (Special Issue on Copyright and Privacy Protection), vol. 16, pp. 587--593, May 1998.

No context found.

I. J. Cox and J. P. M. G. Linnartz, "Some General Methods for Tampering with Watermarks", IEEE Jou. on Selected Areas in Communications, Vol.16, No.4, May 1998, pp.587-593.

No context found.

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE J. Select. Areas Commun., vol. 16, no. 4, pp. 587-593, May 1998.

No context found.

I.J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks", preprint, 1998.

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I. Cox and J.-P. Linnartz, #Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications #Special issue on Copyright and Privacy Protection# 16, pp. 587#593, May 1998.

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I. Cox, J.-P. Linnartz, \Some general methods for tampering with watermarks", in IEEE Journal on Selected Areas in Communications, vol. 16, no. 4, 1988, pp. 587-593.

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Ingemar J. Cox; Jean-Paul M. G. Linnartz. Some general methods for tampering with watermarks. IEEE Journal On Selected Areas in Communications, 16(4):587-593, May 1998.

No context found.

I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications 16, pp. 587--593, May 1998.

No context found.

I.J. Cox and J.-P. Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas of Communications (JSAC), 1997.

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I. J. Cox and J.-P. M. G. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selceted Areas in Communications 16, pp. 587--591, May 1998.

No context found.

I. Cox and J.-P. Linnartz, "Some general methods for tampering with watermarks," IEEE Journal on Selected Areas in Communications (Special issue on Copyright and Privacy Protection) 16, pp. 587--593, May 1998.

No context found.

I. J. Cox and J.-P. M. G. Linnartz. Some general methods for tampering with watermarks. IEEE Journal on Selected Areas in Communications, 16(4):587--593, May 1998.

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