Despite major breakthroughs in multimedia security over the last three decades, video piracy is still striving. Sport leagues are pirated during major live competitions; popular TV shows and series are redistributed on illegal platforms; Hollywood movies are leaked prior to theatrical releases, etc. Similarly to traditional flamenco dancers, one step from service providers to improve the protection of their video platforms leads to another step from the pirates to circumvent such protection.

Camcorder piracy refers to the process of using a camcorder to record a screen that displays copyrighted content. In contrast to the previous works that aimed at detecting the occurrence of camcorder piracy, this paper conducts an in-depth study of the luminance flicker that is naturally present in camcorded videos due to the interplay between a liquid-crystal-display (LCD) screen and a camcorder. We first model the flicker signal and show that its parameters are tied to such internal characteristics of the pirate devices as the back-light frequency of the LCD screen and the read-out time of the camcorder. We then present new estimation techniques to recover these hidden parameters directly from camcorded videos and demonstrate that such forensic cues could provide intelligence on the pirate devices. We also discuss how to recover the shape of the low-power flicker signal itself and show that it could be used to infer which back-light technology employed in the pirate LCD screen.

Spatio-temporal desynchronization remains a major challenge for watermarking system as it could impair the detection of the hidden payload. Over the years, several (non-blind) registration techniques have been proposed to realign the analyzed content prior to watermark detection and thereby achieve robustness against severe attacks such as display-and-camcord. Such techniques rely on assumptions that may be invalidated by new attacks that had not been accounted for. In the case of video, for instance, best-in-class resynchronization techniques may have difficulties to cope with screencasting. In this paper, we report findings after an experimental study that involved five popular screencasting tools. The impact of screencasting can indeed be characterized in terms of frame drops and repeats. Moreover, the on-the-fly encoding process occurring during screen recapture inherently introduces dependencies between the likelihood of drop/repeat and the frame encoding type.

Radial-based 3D watermarking alters the distances between the center of mass of the 3D mesh and its vertices. These watermarking systems are inherently sensitive to cropping. To address this limitation, this paper introduces a complementary blind resynchronization module to transmit critical synchronization information to the watermark decoder. Spherical patterns formed by several secret landmark vertices are embedded alongside the payload and blindly retrieved by the decoder, thereby conveying the synchronization information needed. Experimental results showcase significant improvement against cropping, while preserving performances against valumetric attacks thanks to a control parameter that automatically switches between alternate resynchronization modes.

Correlation-based watermark detection inherently assumes that a pseudo-random watermark pattern is present in the cover signal at a given location. However, disparity-coherent watermarks for stereo video content are broken into pieces which are offset one with respect to the others. Acoustic transmission yields echoes due to multi-path propagation and may thus introduce watermark replicates in the recorded audio track. In such cases, the watermark energy is not concentrated in a single element of the cross-correlation array but rather distributed over a number of them. As a result, it is necessary to devise aggregation strategies to recover these scattered watermarks. In this paper, we present a method that relies on outlier detection to identify which elements of the correlation array are associated to the embedded watermark and should be aggregated. Experimental results clearly demonstrate the ability of this technique to recover the watermark without introducing undesired false positives, even in noisy conditions.

Cryptography-based content protection is an efficient means to protect multimedia content during transport. Nevertheless, content is eventually decrypted at rendering time, leaving it vulnerable to piracy e.g. using a camcorder to record movies displayed on an LCD screen. Such type of piracy naturally imprints a visible flicker signal in the pirate video due to the interplay between the rendering and acquisition devices. The parameters of such flicker are inherently tied to the characteristics of the pirate devices such as the back-light of the LCD screen and the read-out time of the camcorder. In this article, we introduce a forensic methodology to estimate such parameters by analyzing the flicker signal present in pirate recordings. Experimental results clearly showcase that the accuracy of these estimation techniques offers efficient means to tell-tale which devices have been used for piracy thanks to the variety of factory settings used by consumer electronics manufacturers.

HTTP adaptive streaming has become the dominant solution for broadband streaming delivery. Essentially, the server delivers small chunks of content in response to queries from a player, that can alternate between different qualities of content depending on its rendering capabilities and the network condition. In this paper, we highlight that the frequent switches of this popular delivery mechanism are deemed to interfere with the payload modulation of bit-stream video watermarking systems. We then propose a generic strategy to cope with such transmission and showcase its efficiency in practice with a watermarking system that operates directly in the H.264/AVC CABAC bit-stream. Eventually, we evaluate the robustness of the proposed solution against standard attacks.

Collaborative creation workflows are calling for softer protection mechanisms than conventional encryption. Geometry-preserving encryption relates to protection techniques for 3D objects that alter the visual representation of the object after rendering but preserves some geometrical primitives, e.g. the bounding box. The advantage of this approach is the ability of legacy renderers to readily display composite scenes that contain both protected and unprotected objects. In this paper, we introduce a collection of geometry-preserving encryption algorithms, whose visual impact can be adjusted with a tuning parameter, and then report on the influence of the deformation on the actual rendering time of the object. Experimental results clearly highlight that special care needs to be taken in order to preserve interactivity, that is a de facto requirement for collaborative creation.

Content owners are reluctant to deliver premium content to open devices due to the risk of piracy and the corresponding potential for loss of revenue. To lift this deadlock, there is increasing interest in incorporating watermarking-based tracing mechanisms onto mobile devices such as smart phones and tablets. The scarcity of resources calls for innovative watermarking paradigms. In this demo, we will exemplify how two-step bitstream video watermarking could be exploited to address this challenge and why it needs to be adapted to cope with the characteristics of HTTP adaptive streaming.

Modulating the distances between the vertices and the center of mass of a triangular mesh is a popular approach to watermark 3D objects. Prior work has formulated this approach as a quadratic programming problem which minimizes the geometric distortion while embedding the watermark payload in the histogram of distances. To enhance this framework, we introduce two watermarking components, namely the spread transform and perceptual shaping based on roughness information. Benchmarking results showcase the benefits of these add-ons with respect to the fidelity-robustness trade-off.

Content protection relies on several security mechanisms: (i) encryption to prevent access to the content during transport, (ii) trusted computation environment to prevent access during decoding, and we can also add (iii) forensic watermarking to deter content re-acquisition at rendering. With the advent of next generation video and the ever increasing popularity of embedded devices for content consumption, there is a need for new content protection solutions that rely less on hardware. In this context, we propose an architecture that combines the ARM TrustZone technology, an hypervised environment built on Genode and a bit stream watermarking algorithm that inserts serialization marks on the fly in an embedded device. As a result, an attacker cannot get access to video assets in clear form and not watermarked. Reported performances measurements indicate that the induced computational overhead is reasonable.

Today, comparing audio watermarking systems remain a challenge due to the lack of publicly-available reference algorithms. In addition, robustness against acoustic path transmission is only occasionally evaluated. This jeopardizes the chances of digital watermarking to be adopted in the context of applications where such a feature is vital, e.g., second screen, audience measurement, and so on. In this paper, we introduce a rather simple audio watermarking algorithm, whose source code has been publicized for potential reuse by the watermarking community. We then complement this baseline system with three additional components, namely a psychoacoustic model, a resynchronization framework, and an improved correlation-based detector. Reported experimental results clearly demonstrate that the resulting high-fidelity audio watermarking system manages to survive the acoustic path.

A watermarking strategy for triangle surface meshes consists of modifying the vertex positions along the radial directions, in order to adjust the distribution of radial distances and thereby encode the desired payload. To guarantee that watermark embedding does not alter the center of mass, prior work formulated this task as a quadratic programming problem. In this paper, we contribute to the generalization of this formulation with: 1) integral reference primitives; 2) arbitrary relocation directions to alter the vertex positions; and 3) alternate distortion metrics to minimize the perceptual impact of the embedding process. These variants are benchmarked against a range of attacks and we report both improved robustness performances, in particular for simplification attacks, and improved control over the embedding distortion.

Despite the academic focus on blind detection, many forensic watermarking systems actually operate in a non-blind fashion to accommodate for real-life desynchronization attacks. In other words, the original content is needed to perform watermark detection e.g. to re-align the pirate sample with the original content prior to watermark decoding. A somehow intermediate strategy, that could be coined `semi-blind', only requires access to a condensed representation of the original content i.e. content fingerprints. In this paper, we combined a variant of the dynamic time warping algorithm together with multi-dimensional temporal fingerprints to realign pirate video samples. Reported experimental results clearly demonstrate improved accuracy compared to state-of-the-art registration methods for a number of synthetic and real-life attack scenarios.

Video watermarking systems operating directly in the compressed bit stream are receiving increasing interest due to their ease of integration into existing content delivery workflows. Such algorithms, however, usually involve a strong dependency to the underlying video codec. In other words, the throughput of the system, e.g. the embedding rate, is heavily tied to the input bit stream. In this paper, we consider a watermarking system for H.264/AVC CABAC and study its throughput depending on the content mastering process. More precisely, we explore the influence of the compression ratio, the resolution, and some encoding parameters.

We propose a new method to detect resampled imagery. The method is based on examining the normalized energy density present within windows of varying size in the second derivative of the image in the frequency domain, and exploiting this characteristic to derive a 19-D feature vector that is used to train a SVM classifier. Experimental results are reported on 7500 raw images from the BOSS database. Comparison with prior work reveals that the proposed algorithm performs similarly for resampling rates greater than 1, and is superior to prior work for resampling rates less than 1. Experiments are performed for both bilinear and bicubic interpolations, and qualitatively similar results are observed for each. Results are also provided for the detection of resampled imagery with noise corruption and JPEG compression. As expected, some degradation in performance is observed as the noise increases or the JPEG quality factor declines.

The weighted overlap add (WOLA) technique is routinely used in audio processing to avoid introducing audible clicks. This process introduces inter-dependencies between WOLA coefficients and it is thus necessary to revisit watermarking algorithms to accommodate for such dependencies and prevent introducing self-inflicted interferences. In this paper, we focus on an existing phase quantization based audio watermarking system. Instead of the original computationally expensive ad-hoc process for dealing with the inter dependencies between WOLA coefficients, we introduce an alternative strategy. Experimental results show a notable reduction of the complexity while maintaining robustness performances.

3D video content has been receiving increasing interest over the last few months and created challenges regarding how to protect such high valued items. For instance, depth-image-based rendering techniques allowing for the creation of virtual views may impair underlying watermarks embedded within individual views. In contrast with previous works, this article focus on defining a view-independent watermark embedding domain rather than a watermarking system coherent with the disparity across several views, thus permitting blind detection. More specifically, based on the fact that pixel displacements across views most often reduce to horizontal shifts, the average luminance value along the rows of the video frames have been selected for watermark embedding. Experimental results clearly prove the robustness of the watermark against virtual views generation.

We propose a new method to detect re-sampled imagery. The method is based on examining the normalized energy density present within windows of varying size in the second derivative of the frequency domain, and exploiting this characteristic to derive a 19-dimensional feature vector that is used to train a SVM classifier. Experimental results are reported on 7,500 raw images from the BOSS database. Comparison with prior work reveals that the proposed algorithm performs similarly for re-sampling rates greater than 1, and is superior to prior work for re-sampling rates less than 1. Experiments are performed for both bilinear and bicubic interpolation, and qualitatively similar results are observed for each. Results are also provided for the detection of re-sampled imagery that subsequently undergoes JPEG compression. Results are quantitatively similar with some small degradation in performance as the quality factor is reduced.

In this industrial exhibit, Technicolor will showcase various technologies developed to protect digital audio-visual material all along the media value chain, from production to distribution, including forensics services in case pirated content is detected. The exhibit will be organized around Technicolor's proprietary technologies in video fingerprinting and audio/video watermarking.

Motion coherency has recently been identified as a desirable property for watermarks embedded within video streams in order to withstand temporal frame averaging along the motion axis. Nevertheless, no tool has been proposed to easily evaluate the motion coherency of a given watermarking system. Today, this assessment relies on a computationally expensive procedure, namely, (1) embed a watermark, (2) perform temporal frame averaging, and (3) check for the presence of the watermark. In this article, a novel oracle is designed to detect whether a video stream contains any motion-incoherent component or not. Since such incoherence can be introduced by nonmotion-coherent watermarking algorithms, this tool has proven to be most valuable to distinguish watermarked from nonwatermarked content. The oracle relies on some features extracted from error frames after motion compensation. Experimental results demonstrate the efficiency of the proposed method with uncompressed and compressed video streams.

In this paper we argue that improved interoperability between DRM systems is likely to benefit to all the actors in the content value chain. Moreover, we describe a domain-based approach to DRM interoperability. We discuss in some detail configuration aspects of such interoperable domains, and how they affect certain social aspects such as marriage and divorce. We conclude that interoperable domains offer a much needed flexibility, allowing users to more easily move between vertical silos and offering content owners a more flexible environment for selling content.

Recently Zhang et al described an algorithm for the detection of plusmn1 LSB steganography based on the statistics of the amplitudes of local extrema in the greylevel histogram. Experimental results demonstrated performance comparable or superior to other state-of-the-art algorithms. In this paper, we describe improvements to this algorithm to (i) reduce the noise associated with border effects in the histogram, and (ii) extend the analysis to amplitudes of local extrema in the 2D adjacency histogram. Experimental results on a composite database of 7125 images, averaged over a 20-fold cross validation, with classification based on Fisher linear discriminant analysis, demonstrate that the improved algorithm exhibits significantly better performance. The experimetal results are reported in the form of receiver operating characteristic (ROC) curves and summarized by computing the area under the ROC curve (AUC). The new algorithm, using 10 features derived from the ID and 2D histograms, has an AUC value of 0.77 compared to 0.57 for the original algorithm. It also significantly outperforms other state-of-the-art steganalysers.

We compare the performance of three steganalysis system for detection of plusmn1 steganography. We examine the relative performance of each system on three commonly used image databases. Experimental results clearly demonstrate that both absolute and relative performance of all three algorithms vary considerably across databases. This sensitivity suggests that considerably more work is needed to develop databases that are more representative of diverse imagery. In addition, we investigate how performance varies based on a variety of training and testing assumptions, specifically (i) that training and testing are performed for a fixed and known embedding rate, (ii) training is performed at one embedding rate, but testing is over a range of embedding rates, (iii) training and testing are performed over a range of embedding rates. As expected, experimental results show that performance under (ii) and (iii) is inferior to (i). The experimental results also suggest that test results for different embedding rates should not be consolidated into a single score, but rather reported separately. Otherwise, good performance at high embedding rates may mask poor performance at low embedding rates.

Considerable progress has been made in the detection of steganographic algorithms based on replacement of the least significant bit (LSB) plane. However, if LSB matching, also known as -1 embedding, is used, the detection rates are considerably reduced. In particular, since LSB embedding is modeled as an additive noise process, detection is especially poor for images that exhibit high-frequency noise - the high-frequency noise is often incorrectly thought to be indicative of a hidden message. To overcome this, we propose a targeted steganalysis algorithm that exploits the fact that after LSB matching, the local maxima of an images graylevel or color histogram decrease and the local minima increase. Consequently, the sum of the absolute differences between local extrema and their neighbors in the intensity histogram of stego images will be smaller than for cover images. Experimental results on two datasets, each of 2000 images, demonstrate that this method has superior results compared with other recently proposed algorithms when the images contain high-frequency noise, e.g. never-compressed imagery such as high-resolution scans of photographs and video. However, the method is inferior to the prior art when applied to decompressed imagery with little or no high-frequency noise.

Dirty paper trellis codes have been introduced as an alternative to lattice codes to implement watermarking as communications with side information. Their key feature is robustness against valuemetric scaling in comparison with lattice codes. Despite the strong academic recognition, parametrization issues remain unclear. For instance, the impact of the trellis configuration on performance is still not well understood. In this paper, experiments on synthetic signals are reported to investigate how the trellis configuration influences the bit error rate and the computational complexity.

In previous work, we demonstrated how perceptual modeling can be applied to dither modulated quantization index modulation and rational dither modulation, to improve both robustness and fidelity. These algorithms were shown to be significantly more robust to valumetric scaling. However, they, and their predecessors, remain extremely sensitive to re-quantization which commonly occurs due to JPEG compression, numerical rounding and analog-to-digital conversion. It is well known that spread transform dither modulation (STDM) is more robust to re-quantization. In this paper we describe how to incorporate a perceptual model into this framework and present two algorithms based on Watson's perceptual model. Experimental results of robustness to JPEG compression are reported for 1000 images at embedding rates of 1/32 and 1/320. At the high embedding rate, the robustness of the two algorithms is the same as STDM but the perceptual distortion is reduced 23 to about 4, based on Watson's perceptual distance. At the lower embedding rate, we simultaneously observed superior robustness to STDM as well as improved fidelity. If the perceptual distance rather than the document-to-watermark ratio (DWR) is held fixed, then the two adaptive spread transform methods exhibit significant improvements in robustness to JPEG compression

Geometrical distortions are the Achilles heel for many watermarking schemes. Most countermeasures proposed in the literature only address the problem of global affine transforms (e.g., rotation, scaling, and translation). In this paper, we propose an original blind watermarking algorithm robust to local geometrical distortions such as the deformations induced by Stirmark. Our method consists in adding a predefined additional information to the useful message bits at the insertion step. These additional bits are labeled as resynchronization bits or reference bits and they are modulated in the same way as the information bits. During the extraction step, the reference bits are used as anchor points to estimate and compensate for small local and global geometrical distortions. The deformations are approximated using a modified basic optical flow algorithm.

Digital watermarking has been introduced in the 1990s as a complementary technology for copyright protection. In an effort to anticipate hostile behavior of adversaries, the research community is constantly introducing new attacks to benchmark watermarking systems. In this paper, we present a generic attack strategy based on block replacement. As multimedia content is often highly repetitive, the attack exploits signal's self-similarities to replace each signal block with another, perceptually similar one. Guided by the principles of the proposed attack framework, we implemented three attack algorithms for different types of multimedia content: video shots, audio tracks and still images. Finally, considering the effectiveness of the proposed algorithms, we identify the properties that a watermark should have to counter this attacking strategy

Security issues have almost been ignored during the first decade of digital watermarking. As a result, many released watermarking algorithms are weak against hostile intelligence. For instance, block replacement attacks defeat watermarking systems which do not consider the self-similarities of the host signal during embedding. Such attacks replace each signal block with another one, or a combination of other ones, taken at a different location. In this paper, a novel strategy will be presented to generate a signal coherent watermark to achieve immunity against block replacement attacks. The basic idea consists in imposing a linear relationship between watermark samples embedded at different locations, with respect to their local neighborhoods which are characterized with Gabor features.

Dirty paper trellis codes are a form of watermarking with side information. These codes have the advantage of being invariant to valuemetric scaling of the cover work. However, the original proposal requires a computational expensive second stage, informed embedding, to embed the chosen code into the cover Work. In this paper, we present a computational efficient algorithm for informed embedding. This is accomplished by recognizing that all possible code words are uniformly distributed on the surface of a high n-dimensional sphere. Each codeword is then contained within an (n - 1)-dimensional region which defines an n-dimensional cone with the centre of the sphere. This approximates the detection region. This is equivalent to the detection region for normalized correlation detection, for which there are known analytic methods to embed a watermark in a cover work. We use a previously described technique for embedding with a constant robustness. However, rather than moving the cover work to the closest Euclidean point on the defined surface, we find the point on the surface which has the smallest perceptual distortion. Experimental results on 2000 images demonstrate a 600-fold computational improvement together with an improved quality of embedding.

The security issue has been neglected for a long time in digital watermarking. Recent results for video watermarking have pointed out that existing watermarking schemes are not secure, i.e., a hostile intelligence succeeds in removing the hidden watermarks. In particular, for a given secret key, many watermarking schemes embed watermarks which lie in the same low-dimensional subspace whatever the host data is. We show that this subspace can be quite easily estimated with an efficient principal component analysis (PCA). For storage convenience, an online expectation-maximization (EM) algorithm is considered. Once this watermarking subspace has been estimated, an attacker only has to project incoming data onto the orthogonal of this subspace to remove the watermark.

We describe a new watermarking system based on the principles of informed coding and informed embedding. This system is capable of embedding 1380 bits of information in images with dimensions 240 x 368 pixels. Experiments on 2000 images indicate the watermarks are robust to significant valumetric distortions, including additive noise, low-pass filtering, changes in contrast, and lossy compression. Our system encodes watermark messages with a modified trellis code in which a given message may be represented by a variety of different signals, with the embedded signal selected according to the cover image. The signal is embedded by an iterative method that seeks to ensure the message will not be confused with other messages, even after addition of noise. Fidelity is improved by the incorporation of perceptual shaping into the embedding process. We show that each of these three components improves performance substantially.

Recent efforts for watermarking digital video extend the results obtained for still image watermarking. As a result, most of the proposed algorithms rely on a frame-by-frame approach. Such an adaptation leads to unreliable algorithms in terms of security. The goal of this article is to stress the problem of collusion when digital watermarked data is distributed at large scale and especially intra-video collusion in the context of video. Three simple collusion attacks are described before being evaluated on two alternative video watermarking algorithms based on the spread spectrum technique. Finally, some experimental results are presented confirming the danger of intra-video collusion and some perspectives are discussed.

Informed coding is the practice of representing watermark messages with patterns that are dependent on the cover works. This requires the use of a dirty-paper code, in which each message is represented by a large number of alternative vectors. Most previous dirty-paper codes are based on lattice codes, in which each code vector, or pattern, is a point in a regular lattice. While such codes are very efficient to implement, they suffer from inherent weakness against valumetric scaling, such as changes in audio volume or image brightness. In the present paper, we present an alternative to lattice codes that is inherently robust to valumetric scaling. This code is based on a trellis that has been modified so that each bit value may be coded by traversing several alternative arcs. A Viterbi decoder is used in the detector to identify the path with the highest correlation to the input work. Since relative correlation values are unaffected by valumetric scaling, the same message will be detected no matter how the input has been scaled.

During the last decade, a significant effort has been put into designing watermarking algorithms. The watermarking community now needs some advanced attacks and fair benchmarks in order to compare the performances of different watermarking technologies. Moreover, attacks permit the weaknesses of an algorithm to be found and consequently trigger further research in order to overcome the problem. These ideas motivated the creation of the European Certimark project. After a short definition of dewatermarking, we present an original attack based on self similarities. This attack is then put to the test with three different publicly available watermarking tools. Finally, we discuss briefly the feasibility of a generic attack i.e. a dewatermarking attack which should succeed in removing whatever watermarks have been inserted by whatever watermarking tools.