We discuss the use of turbo codes in fingerprinting schemes. More precisely, we present a family of turbo codes that are secure against attacking coalitions of size 2. This family is build upon a class of low-rate convolutional codes with maximum free distance. Low rate convolutional codes are commonly used in code-spread CDMA applications. Moreover, we show how efficient traitor tracing can be performed by means of the turbo decoding algorithm.
Mobile agents are software entities consisting of code, data, and state that can migrate autonomously from host to host
executing their code. In such scenario there are some security issues that must be considered. In particular, this paper deals
with the protection of mobile agents against manipulation attacks performed by the host, which is one of the main security
issues to solve in mobile agent systems. This paper introduces an infrastructure for mobile agent watermarking (MAW).
MAW is a lightweight approach that can efficiently detect manipulation attacks performed by potentially malicious hosts
that might seek to subvert the normal agent operation. MAW is the first proposal in the literature that adapts software
watermarks to verify the execution integrity of an agent. The second contribution of this paper is a technique to punish a
malicious host that performed a manipulation attack by using a trusted third party (TTP) called host revocation authority
(HoRA). A proof-of-concept has also been developed and we present some performance evaluation results that demonstrate
the usability of the proposed mechanisms.
Since the introduction of turbo codes in 1993, many new applications for this family of codes have been proposed. One of the latest, in the context of digital fingerprinting, is called turbo fingerprinting codes and was proposed by Zhang et al.. The main idea is a new fingerprinting code composed of an outer turbo code and an inner code based on the Boneh-Shaw model. The major contribution of this paper is a new analysis of this new family of codes that shows its drawbacks. These drawbacks must be considered in order to perform a correct design of a turbo fingerprinting scheme otherwise the scheme cannot retrieve the traitor users which is the main goal of digital fingerprinting scheme. Moreover, the identification of these drawbacks allows to discuss an entirely new construction of fingerprinting codes based on turbo codes.
Several new video and image watermarking proposals are
based on Informed Coding and Informed Embedding. However, these systems can be not easily used in fingerprinting schemes because they do
not satisfy the marking assumption defined in . In this paper we discuss some guidelines to adapt a watermarking system based on informed coding and informed embedding to a generic fingerprinting code, while keeping up with the marking assumption, that is to say, when as a result of one collusion attack of two users, that have different marks that represent the value 0 in the nth position, we have a pirate mark wich
represents the 0 value in this same nth position. This can be achieved
modifying the work of Miller, Do¨er and Cox in
Soriano, M.; Fernandez, M.; Sayrol, E.; Tomas, J.; Casanellas, J.; Pegueroles, J.; Hernández-Serrano, J. International Conference on Trust Management p. 411-414 DOI: 10.1007/11429760_32 Data de presentació: 2005 Presentació treball a congrés
The work presented in this paper consists in the development of a portable platform to protect the copyright and distribution rights of digital contents, and empirically demonstrate the capacity of several marking and tracing algorithms. This platform is used to verify, at a practical level, the strength properties of digital watermarking and fingerprinting marks. Initially, two watermarking algorithms, one based on spread-spectrum techniques and the other based on QIM (Quantization Index Modulation), have been implemented. Moreover, we use these watermarking algorithms to embed a fingerprinting code, based on code concatenation, equipped with an efficient tracing algorithm. In this paper we focus on the implementation issues of the Java-based platform, that consists of three main packages that are fully described