Hatem Bettahar

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34 ulticasting is an efficient communication mechanism for group-oriented applications such as video conferencing, interactive group games, and video on demand. IP multicast [1 ] saves bandwidth by sending the source traffic on a multicast tree that spans all the members of the group. In this communication model, groups are identified by a group address,(More)
Even though hierarchical group communication is a prominent communication model for a variety of applications, featured by hierarchical communication rules, it has not been sufficiently investigated in the security literature. In this paper, we introduce private hierarchical group communication and we determine its specific confidentiality requirements, and(More)
The phenomenal growths of group communications and QoSaware applications over the Internet have respectively accelerated the development of two key technologies, namely, multicasting and Differentiated Services (DiffServ). Although both are complementary technologies, their integration is a non-trivial task due to architectural conflicts between them. In(More)
Multicasting is increasingly used as an efficient communication mechanism for group-oriented applications in the Internet. In order to offer secrecy for multicast applications, the traffic encryption key has to be changed whenever a user joins or leaves the system. Such a change has to be communicated to all the current users. The bandwidth used for such(More)
Key management in wireless sensor networks (WSN) is a challenging problem because of the limited resources of sensor nodes and their vulnerability against physical attacks. In this paper, we present a two level architecture key management scheme for wireless sensor networks (TLA). Our scheme combines efficiently different key management techniques in each(More)
The phenomenal growths of group communications and QoS-aware applications over the Internet have respectively accelerated the development of two key technologies, namely, multicasting and Differentiated Services (DiffServ). Although both are complementary technologies, their integration is a nontrivial task due to architectural conflicts between them. In(More)
The need for content access control in hierarchies (CACH) appears naturally in all contexts where a set of users have different access rights to a set of resources. The hierarchy is defined using the access rights. The different resources are encrypted using different keys. Key management is a critical issue for scalable content access control. In this(More)