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This paper proposes a theory of watermarking security based on a cryptanalysis point of view. The main idea is that information about the secret key leaks from the observations, for instance, watermarked pieces of content, available to the opponent. Tools from information theory (Shannon's mutual information and Fisher's information matrix) can measure this(More)
This paper discusses a novel strategy for simulating rare events and an associated Monte Carlo estimation of tail probabilities. Our method uses a system of interacting particles and exploits a FeynmanKac representation of that system to analyze their fluctuations. Our precise analysis of the variance of a standard multilevel splitting algorithm reveals an(More)
Content-Based Image Retrieval Systems used in forensics related contexts require very good image recognition capabilities. Therefore they often use the SIFT local-feature description scheme as its robustness against a large spectrum of image distortions has been assessed. In contrast, the <i>security</i> of SIFT is still largely unexplored. We show in this(More)
The class of joint decoder in fingerprinting codes is of utmost importance in theoretical papers to establish the concept of fingerprint capacity. However, no implementation supporting a large user base is known to date. This paper presents an iterative decoder which is the first attempt toward practical large-scale joint decoding. The discriminative(More)
The analysis of the security of watermarking algorithms has received increasing attention since it has been recognized that the sole investigation of robustness issues is not enough to properly address the challenges set by practical applications. Such a security analysis, though, is still in its infancy, up to a point that a general agreement has not yet(More)
This paper proposes a binarization scheme for vectors of high dimension based on the recent concept of anti-sparse coding, and shows its excellent performance for approximate nearest neighbor search. Unlike other binarization schemes, this framework allows, up to a scaling factor, the explicit reconstruction from the binary representation of the original(More)
This paper deals with some detection issues of watermark signals. We propose an easy way to implement an informed watermarking embedder whatever the detection function. This method shows that a linear detection function is not suitable for side information. This is the reason why we build a family of non-linear functions named JANIS. Used with a(More)
This paper presents our recent works on multimedia fingerprinting, improving both the fingerprinting code and the watermarking scheme. Our first contribution focuses on deriving a better accusation process for the well known Tardos codes. It appears that Tardos orginal decoding is very conservative: its performances are guaranteed whatever the collusion(More)
This article presents an asymmetric watermarking method as an alternative to classical Direct Sequence Spread Spectrum and Watermarking Costa Schemes techniques. This new method provides a higher security level against malicious attacks threatening watermarking techniques used for a copy protection purpose. This application, which is quite different from(More)