Security and robustness constraints for spread-spectrum Tardos fingerprinting

International audienceThis paper presents a practical analysis of the impact of robustness and security on Tardos' collusion-secure fingerprinting codes using spread-spectrum watermarking modulations. In this framework, we assume that the coalition has to face an embedding scheme of given security level and consequently has to suffer a probability of wrongly estimating their embedded symbols. We recall the Worst Case Attack associated to this probability, e.g. the optimal attack which minimises the mutual information between the sequence of a colluder and the pirated one. For a given achievable rate of the Tardos' fingerprinting model, we compare the Improved Spread-Spectrum embedding versus a new secure embedding (called rho-Circular Watermarking) considering the AWGN channel. We show that secure embeddings are more immune to decoding errors than non-secure ones while keeping the same fingerprinting capacity

Watermarking security

International audienceThis chapter deals with applications where watermarking is a security primitive included in a larger system protecting the value of multimedia content. In this context, there might exist dishonest users, in the sequel so-called attackers, willing to read/overwrite hidden messages or simply to remove the watermark signal.The goal of this section is to play the role of the attacker. We analyze means to deduce information about the watermarking technique that will later ease the forgery of attacked copies. This chapter first proposes a topology of the threats in Section 6.1, introducing three different concepts: robustness, worst-case attacks, and security. Previous chapter has already discussed watermark robustness. We focus on worst-case attacks in Section 6.2, on the way to measure watermarking security in Section 6.3, and on the classical tools to break a watermarking scheme in Section 6.4. This tour of watermarking security concludes by a summary of what we know and still do not know about it (Section 6.5) and a review of oracle attacks (Section 6.6). Last, Section 6.7 deals with protocol attacks, a notion which underlines the illusion of security that a watermarking primitive might bring when not properly used in some applications

Preserving data integrity of encoded medical images: the LAR compression framework

International audienceThrough the development of medical imaging systems and their integration into a complete information system, the need for advanced joint coding and network services becomes predominant. PACS (Picture Archiving and Communication System) aims to acquire, store and compress, retrieve, present and distribute medical images. These systems have to be accessible via the Internet or wireless channels. Thus protection processes against transmission errors have to be added to get a powerful joint source-channel coding tool. Moreover, these sensitive data require confidentiality and privacy for both archiving and transmission purposes, leading to use cryptography and data embedding solutions. This chapter introduces data integrity protection and developed dedicated tools of content protection and secure bitstream transmission for medical encoded image purposes. In particular, the LAR image coding method is defined together with advanced securization services

Practical Performance Analysis of Secure Modulations for WOA Spread-Spectrum based Image Watermarking

International audienceThis paper presents the first practical analysis of secure modulations for watermarking of still images in the case of a WOA (Watermarked Only Attack) attack framework (the attacker observes only marked contents). Two recent spread spectrum modulations, namely Natural Watermark- ing (NW) and Circular Watermarking (CW) are compared against classical modulations, namely Spread Spectrum (SS) and Improved Spread Spectrum (ISS). Results are discussed from the distorsion point of view, as well as from the the ro- bustness and security point of view. We emphasize that the experiments were carried out on a rather significant num- ber of images (2000) and demonstrate the relevance of these modulations in a real-world application

Central Washington University 2018-2019 Undergraduate Catalog

https://digitalcommons.cwu.edu/catalogs/1180/thumbnail.jp