Host mobility key management in dynamic secure group communication

The key management has a fundamental role in securing group communications taking place over vast and unprotected networks. It is concerned with the distribution and update of the keying materials whenever any changes occur in the group membership. Wireless mobile environments enable members to move freely within the networks, which causes more difficulty to design efficient and scalable key management protocols. This is partly because both member location dynamic and group membership dynamic must be managed concurrently, which may lead to significant rekeying overhead. This paper presents a hierarchical group key management scheme taking the mobility of members into consideration intended for wireless mobile environments. The proposed scheme supports the mobility of members across wireless mobile environments while remaining in the group session with minimum rekeying transmission overhead. Furthermore, the proposed scheme alleviates 1-affect-n phenomenon, single point of failure, and signaling load caused by moving members at the core network. Simulation results shows that the scheme surpasses other existing efforts in terms of communication overhead and affected members. The security requirements studies also show the backward and forward secrecy is preserved in the proposed scheme even though the members move between areas

Separation of Oligosaccharides from Lotus Seeds via Medium-pressure Liquid Chromatography Coupled with ELSD and DAD

peer-reviewedLotus seeds were identified by the Ministry of Public Health of China as both food and medicine. One general function of lotus seeds is to improve intestinal health. However, to date, studies evaluating the relationship between bioactive compounds in lotus seeds and the physiological activity of the intestine are limited. In the present study, by using medium pressure liquid chromatography coupled with evaporative light-scattering detector and diode-array detector, five oligosaccharides were isolated and their structures were further characterized by electrospray ionization-mass spectrometry and gas chromatography-mass spectrometry. In vitro testing determined that LOS3-1 and LOS4 elicited relatively good proliferative effects on Lactobacillus delbrueckii subsp. bulgaricus. These results indicated a structure-function relationship between the physiological activity of oligosaccharides in lotus seeds and the number of probiotics applied, thus providing room for improvement of this particular feature. Intestinal probiotics may potentially become a new effective drug target for the regulation of immunity

Fault-tolerant and Scalable Key Management Protocol for IoT-based Collaborative Groups

International audienceSecuring collaborative applications relies heavily on the underlying group key management protocols. Designing these protocols ischallenging, especially in the context of the Internet of Things (IoT). Indeed, the presence of heterogeneous and dynamic members within the collaborative groups usually involves resource constrained entities, which require energy-aware protocols to manage frequent arrivals and departures of members. Moreover, both fault tolerance and scalability are sought for sensitive and large collaborative groups. To address these challenges, we propose to enhance our previously proposed protocol (i.e. DBGK) with polynomial computations. In fact, our contribution in this paper, allows additional controllers to be included with no impact on storage cost regarding constrained members. To assess our protocol called DsBGK, we conducted extensive simulations. Results confirmed that DsBGK achieves a better scalability and fault tolerance compared to DBGK. In addition, energy consumption induced by group key rekeying has been reduced

Enhanced WEP : An efficient solution to WEP threats

Security is a strong requirement for effective deployment of business wireless communication applications. Therefore, many proposals dealt with security holes in wired equivalent privacy protocol (WEP). In this paper, we analyze WEP security holes and we propose an improvement over WEP which achieves, in addition to its security goals, another security service which is replay detection. Our premise is to permit deploying an efficient security mechanism on wireless networks, without reconsidering all the security architecture. Contrary to the standards WPA proposed by the Wi-Fi Alliance and IEEE 802.11 proposed by the task group I of IEEE 802.11, our solution requires neither hardware add-on nor replacement, but merely software updates

Hi-KD : Hash-based hierarchical Key Distribution for Group Communication

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, then we propose an efficient key management protocol satisfying those requirements. This work is done in the frame of a national french project whose consortium includes the international telecom company EADS, INRIA, CNRS and ENST-Paris. The project is called Safe- Cast and deals with group communication in PMR networks that are used mainly by security corps (police, fire fighters,soldiers,. . . ) in areas where it is difficult to have network infrastructures, such as war battles or following a natural disaster (earthquake, tsunami, tornado, . . . )

Key management for content access control in a hierarchy

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 paper, we study the problem of key management for CACH. We present main existing access control models, and show why these models are not suitable to the CACH applications, and why they are not implemented in the existing key management schemes. Furthermore, we classify these key management schemes into two approaches, and construct an access control model for each approach. The proposed access control models are then used to describe the schemes in a uniform and coherent way. A final contribution of our work consists of a classification of the CACH applications, a comparison of the key management schemes, and a study of the suitability of the existing schemes to the CACH applications with respect to some analytical measurements