This paper presents a traitor tracing method dedicated to video content distribution. It is based on a two-level
approach with probabilistic traitor tracing codes. Codes are concatenated and decoded successively, the first
one is used to decrease the decoding complexity and the second to accuse users. We use the well-known Tardos
fingerprinting code for the accusation process and a Boneh-Shaw code with replication scheme to reduce the
search space of users. This method ensures a decrease of the computational time compared to classical Tardos
codes decoding. We present a method to select suspect groups of users and compare it to a more complex
two-level Tardos code which follows the same construction.
This paper presents a traitor tracing method dedicated to video content distribution. It is based on a probabilistic
traitor tracing code and an orthogonal zero-bit informed watermark. We use the well-known Tardos fingerprinting
tracing function to reduce the search space of suspicious users. Their guiltiness is then confirmed by detecting
the presence of a personal watermark embedded with a personal key. To prevent watermarking key storage at
the distributor side, we use a part of the user probabilistic fingerprinting sequence as a personal embedding key.
This method ensures a global lower false alarm probability compared to original probabilistic codes. Indeed, we
combine the false alarm probability of the code with the false alarm probability of the watermarking scheme.
However the efficiency of this algorithm strongly depends on the number of colluders at the watermarking side.
To increase the robustness, we present an additive correlation method based on successive watermarked images,
we then study its limitation under different sizes of collusion.
The Good is Blondie, a wandering gunman with a strong personal sense of honor. The Bad is Angel Eyes, a sadistic hitman who always hits his mark. The Ugly is Tuco, a Mexican bandit who's always only looking out for himself. Against the backdrop of the BOWS contest, they search for a watermark in gold buried in three images. Each knows only a portion of the gold's exact location, so for the moment they're dependent on each other. However, none are particularly inclined to share...
Using electronic watermarks as copyright protection for still images requires robustness against geometrical attacks. In this paper we propose a watermarking scheme that is robust to rotation and scaling distortions. The watermark detection is performed in a 1-D invariant signature whereas the embedding process is performed adding a watermark signal in the DFT domain. This embedding procedure allows the watermarking signal to be shaped in the frequency domain. This shaping is determined solving a game opposing the watermarker and the attacker. Statistically significant roc curve test results under several attacks are presented.
Proc. SPIE. 5306, Security, Steganography, and Watermarking of Multimedia Contents VI
KEYWORDS: Signal to noise ratio, Data modeling, Data hiding, Interference (communication), Distortion, Demodulation, Digital watermarking, Discrete wavelet transforms, Performance modeling, Systems modeling
Data hiding has been mainly studied in the last years. Many applications are
targeted such as copy-rights management, meta-data embedding for rich-media
applications, ... In all these applications, it is crucial to estimate what
is the capacity of data hiding. Many works have then been made to study
watermarking performance considering data-hiding as a kind of channel
communication. However in all these studies, an assumption is made about the
perfect knowledge of all attacks parameters (may be known in advance or later
estimated with attacks modeling). More especially a malicious attacker may
biased its attack so that parameters estimation may not be perfect
(desynchronization in parameters). Furthermore, random geometrical attacks
for images such as proposed by Stirmark benchmark (more generally
desynchronization attacks) show that perfect synchronization may not also be
achievable. These last kind of attacks are actually the most effective and
lack of theoretical modeling for capacity estimation. We then propose a new
model for taking into account desynchronization phenomenon in data hiding
(coupled with degrading attacks - i.e. optimal SAWGN attacks). Further,
thanks to the use of game theory, we state bounds on the capacity that may be
obtained by data hiding systems when subject to desynchronization.
Nowadays, a popular method used for additive watermarking is wide spread spectrum. It consists in adding a spread signal into the host document. This signal is obtained by the sum of a set of carrier vectors, which are modulated by the bits to be embedded. To extract these embedded bits, weighted correlations between the watermarked document and the carriers are computed. Unfortunately, even without any attack, the obtained set of bits can be corrupted due to the interference with the host signal (host interference) and also due to the interference with the others carriers (inter-symbols interference (ISI) due to the non-orthogonality of the carriers). Some recent watermarking algorithms deal with host interference using side informed methods, but inter-symbols interference problem is still open. In this paper, we deal with interference cancellation methods, and we propose to consider ISI as side information and to integrate it into the host signal. This leads to a great improvement of extraction performance in term of signal-to-noise ratio and/or watermark robustness.