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With the increasing interest in public cloud infrastructures, a crucial need has evolved for trustworthy remote data storage and processing. At the same time the increased demand for storage, from backup services, to cloud infrastructures has driven the use of deduplication to eliminate redundant data in the cloud as a means to improve storage efficiency, and save bandwidth, reducing the cost of deploying...
The biometric de-duplication problem examines whether an input biometric sample has a corresponding match in a reference database during the enrollment process. If the input biometric is deemed to have a match, then the individual is not enrolled as a new identity in the database in order to prevent duplicate entries; otherwise, a new identity profile is created and the individual is enrolled in the...
We revisit recent results from the area of collusion-resistant traitor tracing, and show how they can be combined and improved to obtain more efficient dynamic traitor tracing schemes. In particular, we show how the dynamic Tardos scheme of Laarhoven et al. can be combined with the optimized score functions of Oosterwijk et al. to trace coalitions much faster. If the attack strategy is known, in many...
Watermarking and data hiding are important tools to protect digital multimedia contents. To reduce the interference effect of the host signal for the conventional multiplicative Spread Spectrum (MSS) embedding scheme, this paper proposes a novel correlation-and-bit-aware multiplicative Spread Spectrum (CMSS) embedding scheme. This scheme exploits the correlation between the host signal and the watermark...
As a typical reversible data hiding scheme, the performance of histogram shifting (HS) technique is dependent on the selected side information, i.e., peak and zero bins. Due to the massive solution space and burden in distortion computation, the conventional HS based schemes utilize some empirical criterions to determine those side information. In this paper, the rate and distortion model and the...
Fraudulent identities of multiple enrollments usually link to fraud and serious breaches of law. With the vast biometric data collection, identity de-duplication has become the processing bottleneck of biometric enrollments. Recently, locality sensitive hashing (LSH) based methods have been introduced for fast retrieval of biometric identities. Most of them are working in the binary space. This paper...
Searching a Peer-to-Peer (P2P) network without using a central index has been widely investigated but proved to be very difficult. Various strategies have been proposed, however no practical solution to date also addresses privacy concerns.
We study collusion-resistant traitor tracing in the simple decoder approach, i.e. assignment of scores for each user separately. We introduce a new score function for non-binary bias-based traitor tracing. It has three special properties that have long been sought after: (i) The expected score of an innocent user is 0 in each content position. (ii) The variance of an innocent user's score is 1 in...
Currently, many forensic techniques have been developed to determine which processing operations were used to manipulate a multimedia signal. Determining the order in which these operations were applied, however, remains an open challenge. Understanding this order is important because it not only provides greater insight into a signal's processing history, but it can also be used to determine a forger's...
Buyer-seller watermarking protocols are protocols that let a seller embed a watermark which uniquely identifies the buyer of each sold copy of some work without allowing the seller to learn the watermark. The purpose of such protocols is to deter buyers from illegally redistributing the work while protecting the buyer from being framed by dishonest sellers. Existing buyer-seller watermarking schemes...
The problem of resampling factor estimation as a means for tampering detection has been largely investigated. Most of the existing techniques rely on the analysis of cyclic correlations induced in the resampled signal. However, in this paper, a new direction is explored by addressing the same problem in terms of the set-membership estimation theory. The proposed technique constructs a model of the...
Slepian's variant I permutation coding has been recently shown to be a fundamental steganographic tool, as it implements optimum perfect steganography of memoryless sources. Although real host signals are not memoryless, a decorrelating energy-preserving transform can always be applied before a method that assumes a memoryless source, as is usually done in the dual problem of source coding. A further...
In this paper, we investigate the problem of deciding whether a multidimensional signal has been quantized according to a given lattice or not. Under an infinite variance assumption, we derive the expression of the optimal detector, together with a practical approximation formula based on multidimensional Fourier series. As a forensic case study, the proposed detector is applied to the detection of...
Image forensics aims at detecting clues regarding the history of a digital image. However, many forensic techniques present some limitations in real life scenarios, where the application of post-processing operators may alter the characteristic footprints exploited by forensic tools. In this paper we study the combination of JPEG compression and full-frame linear filtering, analyzing their impact...
In the past few years, thanks to the increasing availability of multimedia sharing platforms, the online availability of user generated content has incredibly grown. However, since media sharing is often not well regulated, copyright infringement cases may occur. One classic example is the pirate distribution of audio bootlegs, i.e., concerts illegally recorded using portable devices. In order to...
This paper proposes a novel framework for image splicing detection based on the inconsistency in the blur degree and depth information of an image. Firstly, the blur kernels of image blocks (local blur kernels) are estimated. Next, a multi-step reblurring technique is used to measure the relative blur degrees of the local blur kernels. The relative blur degrees are used as a feature to classify the...
In this paper, we proposed shot-based temporally respective frame (TRF) generation algorithm for video hashing. The edge change ratio (ECR) is adopted to measure the dissimilarity between different video frames. The maximum value of ECR inside a temporal sliding window is compared with a given threshold to determine the shot boundary. We weight the frames in the same shot to generate the temporally...
Linking two network flows that have the same source is essential in intrusion detection or in tracing anonymous connections. To improve the performance of this process, the flow can be modified (fingerprinted) to make it more distinguishable. However, an adversary located in the middle can modify the flow to impair the correlation by delaying the packets or introducing dummy traffic. We introduce...
Image Forensics (IF) is a challenging research topic, that suffers from strong limitations when facing with real world applications. A possible way to cope with these limitations is to resort to data fusion, whereby the outputs of different forensic tools are used to reach a final decision about the analyzed image. Nevertheless, existing schemes do not take full advantage of all the information available...
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