The dynamics of the CBC Mode of Operation

In cryptography, the Cipher Block Chaining (CBC), one of the most commonly used mode in recent years, is a mode of operation that uses a block cipher to provide confidentiality or authenticity. In our previous research work, we have shown that this mode of operation exhibits, under some conditions, a chaotic behaviour. We have studied this behaviour by evaluating both its level of sensibility and expansivity. In this paper, we intend to deepen the topological study of the CBC mode of operation and evaluate its property of topological mixing. Additionally, other quantitative evaluations are performed, and the level of topological entropy has been evaluated too.Comment: Nonlinearity, IOP Publishing, 2016. arXiv admin note: text overlap with arXiv:1601.0813

Detecting Inference Channels in Private Multimedia Data via Social Networks

International audienceIndirect access to protected information has been one of the key challenges facing the international community for the last decade. Providing techniques to control direct access to sensitive information remain insufficient against inference channels established when legitimate data reveal classified facts hidden from unauthorized users. Several techniques have been proposed in the literature to meet indirect access prevention. However, those addressing the inference problem when involving multimedia objects (images, audio, video, etc.) remain few and hold several drawbacks. In essence, the complex structure of multimedia objects makes the fact of detecting indirect access a difficult task. In this paper, we propose a novel approach to detect possible inference channels established between multimedia objects representing persons by combining social network information with unmasked content of multimedia objects. Here, we present the techniques used to map the content of social networks to the set of multimedia objects at hand. We also provide an MiD function able to determine whether an unmasked multimedia object combined with data from the social network infers a sensitive multimedia object

A Fine-Grained Image Access Control Model

International audienceSharing and publishing images and photos have become the trend of nowadays (social networks, messengers, etc.). Providing appropriate techniques to preserve privacy and protect content of sensitive and private images is an essential need. In this paper, we present a novel security model for image content protection. In our model, we provide dynamic security rules based on first order logic to express constraints that can be applied to contextual information as well as low level features of images. We finally discuss a set of experiments and studies carried out to evaluate the proposed approach. \textcopyright 2012 IEEE

Bridging Sensing and Decision Making in Ambient Intelligence Environments

Context-aware and Ambient Intelligence environments represent one of the emerging issues in the last decade. In such intelligent environments, information is gathered to provide, on one hand, autonomic and easy to manage applications, and, on the other, secured access controlled environments. Several approaches have been defined in the literature to describe context-aware application with techniques to capture and represent information related to a specified domain. However and to the best of our knowledge, none has questioned the reliability of the techniques used to extract meaningful knowledge needed for decision making especially if the information captured is of multimedia types (images, sound, videos, etc.). In this chapter, we propose an approach to bridge the gap between sensing and decision making and provide an uncertainty resolver to reduce faulty decisions based on uncertain knowledge extracted from unreliable techniques.We describe also a set of experiments elaborated to demonstrate the efficiency of our uncertainty resolver

Security and Privacy Preserving in Social Networks

XVI, 367 p. 107 illus., 66 illus. in color.onlin

The Image Protector - A Flexible Security Rule Specification Toolkit

International audienceThe tremendous sharing of multimedia objects on the web shed the light on several privacy concerns related in essence to the safe publishing of end users' personal data. Providing techniques to protect multimedia objects faces several difficulties due to multimedia objects' heterogeneous and complex structure on one hand, and on the other hand, the wide range of information that could be used to describe their content. In this paper, we present a flexible security rule specification toolkit for multimedia objects. Our toolkit is based on a security model and a core ontology in which we populate the model's related information and multimedia objects data. To specify security rules, we use the SWRL language in order to address both, the content and the context of multimedia objects

Enforcing role based access control model with multimedia signatures

International audienceRecently ubiquitous technology has invaded almost every aspect of the modern life. Several application domains, have integrated ubiquitous technology to make the management of resources a dynamic task. However, the need for adequate and enforced authentication and access control models to provide safe access to sensitive information remains a critical matter to address in such environments. Many security models were proposed in the literature thus few were able to provide adaptive access decisions based on the environmental changes. In this paper, we propose an approach based on our previous work [B.A. Bouna, R. Chbeir, S. Marrara, A multimedia access control language for virtual and ambient intelligence environments, In Secure Web Services (2007) 111-120] to enforce current role based access control models [M.J. Moyer, M. Ahama, Generalized role-based access control, in: Proceedings of International Conference on Distributed Computing Systems (ICDCS), Phoenix, Arizona, USA, 2001, pp. 391-398] using multimedia objects in a dynamic environment. In essence, multimedia objects tend to be complex, memory and time consuming nevertheless they provide interesting information about users and their context (user surrounding, his moves and gesture, people nearby, etc.). The idea behind our approach is to attribute to roles and permissions, multimedia signatures in which we integrate conditions based on users' context information described using multimedia objects in order to limit role activation and the abuse of permissions in a given environment. We also describe our architecture which extends the known XACML [XACML, XACML Profile for Role Based Access Control (RBAC), , 2008] terminology to incorporate multimedia signatures. We provide an overview of a possible implementation of the model to illustrate how it could be valuable once integrated in an intelligent environment

Secure Outsourcing of Network Flow Data Analysis

In this paper, we identify a new and challenging application for the growing field of research on data anonymization and secure outsourcing of storage and computations to the cloud. Network flow data analysis is of high importance for network monitoring and management. Network monitoring applications reveal new challenges not yet addressed in the secure outsourcing literature. The secure and verifiable outsourcing of computation on anonymized network flow records provides a practical tool for network operators in order to harness the cloud benefits, which untapped until now because of privacy concerns. We present representative use-cases and problems, and identify sample related work that can be utilized for developing an effective solution