Research

Research Activity

WAVECOP (Funded by the Italian Ministery - PRIN 2003)

There is today a great interest both at the European and International level on Digital Rights Management (DRM) technologies, due to the proliferation of multimedia documents piracy, made easy by the large diffusion of digital processing tools and telecommunications networks. An important brick in the construction of a DRM solution can be represented by watermarking. The aim of this Project is to further promote the Italian research in the data hiding and watermarking field, and to co-ordinate the activities of the Research Units (RU) in such a way to increase their effectiveness. This will be achieved, on one hand by strengthening the know-how of the RU on the basic theoretical aspects of this technology, and on the other hand, by investigating practical solutions for 4 different applications, namely: Robust watermarking for multimedia copyright protection; Secure watermarking tools for multimedia documents; Security and conditional access for video streaming using watermarking; Robust watermarking of multispectral images.

SECUREMS: SECUrity for REMote Sensing (Funded by the Italian Space Agency fo the years 2001-2003)

Recent advances in electronic distribution of digital data in open network environments, and the wider and wider availability of remote sensing imagery, justify the growing interest towards large scale commercialisation of remote sensing products. Along with the commercial interest towards the global sale of satellite images, the demand for secure protection mechanisms enabling the enforcement of copyright laws has grown as well. The objective of SECUREMS (SECUrity for REMote Sensing) Project was to study the particular issues related to the watermarking of remote sensing imagery, and to develop innovative algorithms for both robust watermarking and watermarking-based authentication of this kind of data.

ECRYPT: European Network of Excellence in Cryptology (funded by EU under 6PF for the years 2004-2007)

ECRYPT - is a 4-year network of excellence funded within the Information Societies Technology (IST) Programme of the European Commission's Sixth Framework Programme (FP6) under contract number IST-2002-507932. It falls under the action line Towards a global dependability and security framework. ECRYPT was launched on February 1st, 2004. Its objective is to intensify the collaboration of European researchers in information security, and more in particular in cryptology and digital watermarking.

Secure Watermarking for Digital Rioghts Management (Funded by the University of Siena - PAR 2003)

The design of a secure watermarking system for copyright protection applications and Digital Rights Management is one of the major challenges watermarking researchers are facing with. This is due to the very hostile environment presented by copyright protection applications, where the presence of an enemy explicitly aiming at removing or making the watermark unreadable must be taken into account. With the further complication that it has always to be assumed that the pirate knows all the details of the watermarking algorithm, and that security relies only on the secrecy of a key K called secret key. Within this framework, the goal of this project is twofold. A first objective consists in the incorporation of security issues within the watermarking theoretical models available today. This goal will be carried out by explicitly considering the possibility that the pirate discovers some of the information that was meant to be kept secret. In most cases, in fact, the main threat to security is represented by the possibility that the pirate manages to reveal the secret information (e.g. the secret key K) or part of it. A possible way to analyze this kind of attacks is to cast the leakage of information in favor of the pirate in an information-theoretic framework, where the leakage is measured in terms of mutual information between the data observable by the pirate and the secret information itself. As a second goal, innovative solutions will be developed for secure watermarking. Specifically, innovative asymmetric watermarking schemes will be sought for that improve the current state of the art with respect to robustness against standard host data manipulations (watermark robustness). In addition, given that most of the asymmetric watermarking schemes proposed so far solely allow to detect the presence of a known watermark (detectable watermarking), efforts will be devoted to examine the possibility to develop multibit (readable) asymmetric watermarking algorithms.

Analysis and development of distributed source coding techniques for remote sensing applications (funded by the University of Siena, PAR 2005)

Distributed Source Coding (DSC) addresses the problem of the separate coding of two or more correlated sources of information, while reaching the same performance of a joint coder. Although the possibility of achieving such a surprising result has been proved theoretically about 30 years ago, its practical application to real data has been considered only recently. The aim of this project is to apply the DSC concepts to two remote sensing scenarios. The first scenario considers the compression of hyperspectral images on board of a satellite platform. The bands of the hyperspectral image are seen as a set of correlated sources that should be coded jointly in order to achieve the theoretically achievable performance predicted by Shannon. Due to the necessity of keeping the complexity of the satellite platform as low as possible, it is mandatory that simple compression algorithms are used, hence making the joint coding of image bands difficult to achieve. By applying the DSC paradigm, the compression efficiency of a joint coder can be achieved by a much simpler band-by-band coder. The reduced complexity of the encoder is paid by increasing the complexity of the decoder. However, this is not a problem, since image reconstruction is usually performed at the ground station, for which no particular computational constraint exists. The second scenario regards the compression of an image on board of a satellite, when a similar image already exist in the archive of the ground station. This is typically the case of a series of images framing the same scene acquired at different time instants. In this case the project will investigate the possibility of applying DSC to transmit only the “innovation” of the new image with respect to the images available at the decoder. Significant advantages in terms of efficient exploitation of the downlink channel are expected so to increase the amount of data transmitted from the satellite to the ground stations.

SPEED: Signal Processing in the EncryptEd Domain (funded by the EU under FP& for the period 2006-2009)

The goal of SPEED is to foster the advancement of the marriage between Signal Processing and Cryptographic techniques, both at theoretical and practical level. The objective is the initiation and development of a totally new and unexplored interdisciplinary framework and technologies for signal processing in the encrypted domain (s.p.e.d.). As a result, entirely new solutions will emerge to the problem of security in multimedia communication/consumption, and digital signal manipulations. Most of technological solutions proposed so far to cope with multimedia security simply tried to apply some cryptographic primitives on top of the signal processing modules. These solutions are based on the assumption that the two communicating parties trust each other, so that the encryption is used only to protect the data against third parties. In many cases, though, this is not the case. Recently, some pioneering works addressing a few scattered scenarios have pointed out that a possible solution to the above problems could consist in the application of the signal processing modules in the encrypted domain. It is the aim of SPEED to foster the birth of the new s.p.e.d. discipline and to demonstrate its ability to provide solutions to the call for security stemming from some selected application scenarios, including multimedia security and privacy-preserving access to sensitive contents. SPEED research activity will be carried out both at a theoretical and a practical level, the theoretical part being dedicated to the development of a general framework investigating the fundamental limits and trade-offs of s.p.e.d., and the practical part being devoted to the development of some of the basic s.p.e.d. building blocks and to their application in some selected scenarios. The project will end with the validation of the proposed solutions by means of a demonstrator.

Digital watermarking of still images in the presence of de-synchronization attacks: theoretical analysis and development of practical algorithms (Funded by the Italian Ministery under FIRB programme for the years 2006-2009)

The use of digital watermarking in real applications is impeded by the weakness of current algorithms against desynchronization attacks. Despite their importance, no thorough theoretical analysis of the desynchronization problem is available, most of the studies being limited to the description of partial solutions.This project aims at filling this gap, first of all by analysing the desynchronization problem at a very general and theoretical level, by exploiting some new information theoretic tools, then by testing the theoretical analysis on synthetic and real data, and finally by developing a new class of watermarking algorithms that are robust against desynchronization.

Prof. Mauro Barni		tel. +39 0577234621