Every group member contributes a share of the final common groupkey, to form a common groupkey in the proposed approach. The groupkey can be refreshed periodically or only be updated in response to changes of group membership. The updating of the groupkey helps to enforce backward and forward secrecy of group communications. Obviously, efficiently exchanging keying materials is critical in MANETs. In SERGK, all keying materials are disseminated through the underlying multicast tree links. A native broadcast through flooding is obviously not appropriate because of large redundancy which may result in network traffic congestion. There are many multicast routing protocols that have been proposed, and they are described in Section 2. Here, a reliable double multicast tree formation and maintenance protocol is presented. This idea is similar to Wei and Zakhor , however, the double tree scheme guarantees that two trees cover all group members. Logically, the two trees are identical from a group member’s point of view. In Wei and Zakhor (2004), some group members included in one tree might not be included in the other tree, which is obviously not desirable for groupkeymanagement. The multicast routing protocol serves as a subsystem of our groupkeymanagement framework. The detailed protocols are presented as follows.
In this paper, we presented the concept of an efficient group-key-management protocol that meets the require- ments of resource-efficient procedures in many applica- tion scenarios like MANET. It is based on the combina- tion of the lightweight G-IKEv2  communication protocol in combination with CAKE  for the key exchange and keymanagement. CAKE offers the pos- sibility to exchange keys within a group and to react ef- ficiently to dynamic changes of the group with low cal- culation effort and a low load on the network. Neverthe- less, it enables confidential key distribution and compli- ance with backward and forward security requirements for mobile computing. The main objective to reduce the network load to a minimum is achieved at the cost of additional storage space for supplement cryptographic key material. The CRT-based key hierarchy together with a ternary keys tree structure reduce the data to be transferred especially during group leave operations. The design of CAKE delegates computational demand- ing cryptographic operations to the group controller, re- lieving to potentially less powerful group members. In today’s interconnected world, this middleware technol- ogy shows advantageous in the area of secure group communication among highly constrained group mem- bers.
 R. Varalakshmi and Dr. V. Rhymend Uthariaraj, “A New Secure Multicast GroupKeyManagement (NSMGKM)Using Gray Code” IEEE –International Conference on Recent Trends in Information Technology, ICRTIT 2011, Anna University, june 2011.  G. H. Chiou and W. T. Chen, “Secure broadcast using
The DGKM approach involves splitting a large group into small subgroups. Each subgroup has a subgroup controller which is responsible for the keymanagement of its subgroup. The first DGKM scheme to appear was IOLUS . The CGKA schemes involve the participation by all members of a group towards keymanagement. Such schemes are characterized by the absence of the GC. The groupkey in such schemes is a function of the secret shares contributed by the members.Typical CGKA schemes include binary tree based ones  and n-party Diffie-Hellman key agreement [5, 6]. Tree Based Group Diffie Hellman (TGDH) is a groupkeymanagement scheme proposed in . The basic idea is to combine the efficiency of the tree structure with the contributory feature of DH. The DGKD scheme, proposed in , eliminates the need for a trusted central authority and introduces the concepts of sponsors and co distributors. All group members have the same capability and are equally trusted. Also, they have equal responsibility, i.e. any group member could be a potential sponsor of other members or a co-distributor. Whenever a member joins or leaves the group, the member’s sponsor initiates the rekeying process. The sponsor generates the necessary keys and securely distributes the keys to co-distributors respectively. The co distributors then distribute in parallel, corresponding keys to corresponding members. In addition to the above four typical classes of keymanagement schemes, there are some other forms of keymanagement schemes such as hierarchy and cluster based ones [6, 8]. A contributory groupkey agreement scheme is most appropriate for SGC in this kind of environment.
Multicasting may be a productive secure group communication components in UAV (Unmanned autonomous vehicles) – MBN (Mobile ad hoc networks) to distribute groupkey to a variety of recipients. During this paper, we have a tendency to propose a secure information group action and economical delivery of groupkeymanagement theme, hybrid groupkeymanagement (HGKM), for multicasting. This approach, contrasted with the Logical Key Hierarchy (LKH), GroupKeyManagement Protocol (GKMP), and One-Way Function Tree (OFT) in multicast groupkeymanagement approaches, we can improve the operation efficiency of wireless network Environment.
The BALADE groupkeymanagement protocol brings a profit in the average delay of keys transmission, evaluated up to 30% compared to DMGSA and 90% compared to GKMPAN (cf Figure 3). This gain is due to the OMCT clustering process of BALADE, which ensures a highly correlated clusters. The keys transmission delay is than strongly dependent of the cohesion of the clusters around their local controllers. The efficiency of the key distribution process in BALADE is followed by a satisfying level of reliability (cf. Figure 5). BALADE brings a profit in term of keys delivery rate, varying from 20% to 40% compared to DMGSA for the high densities of members (in a surface of 500*500). Indeed, the keys distribution follows 1-hop ways between the clusterheads and their local members, thus minimizing the loss and interferences rate. Only the distribution of the groupkey follow a multi-hop ways between the global controller and the local controllers.
In Mobile AdHoc Networks (MANETs), data transmission is speeded up by means of multicasting. Though multicast transmission lessens overhead, collision and congestion, it persuades new challenges towards security management. This challenge must be conquered to bring better throughput of the network. In this paper, we introduce a multi level groupkeymanagement technique for multicast security in MANET. Our technique works in a hierarchical model such that cluster heads are prioritized over cluster members. The secure keys are generated using one-way function chain. In addition to secure keymanagement, the issue of mobility is also handled. By simulation results, we prove the proficiency of our proposed technique. Our secure keymanagement technique incurs low overhead and delay and significantly increases the throughput.
ABSTRACT: Groupkeymanagement is one of the basic building blocks in collaborative and group-oriented applications in Mobile Ad Hoc Networks (MANETs). Groupkey establishment involves creating and distributing a common secret for all group members. However, keymanagement for a large and dynamic group is a difficult problem because of scalability and security. Dynamical changes in network’s topology causes feeble conviction relationship among the nodes in the network. In MANETs a mobile node operates as end terminal as well as an midway router. Therefore, a multi-hop situation occurs for communication in MANETs; where in between source and destination there may be one or more malicious nodes. In this paper, we proposed a keymanagement scheme. We assume that MANETs is alienated into groups having a group leader in each group. Group leader has accountability of keymanagement in its group. Proposed keymanagement scheme is a decentralized method that does not need any Trusted Third Party (TTP) for keymanagement. In proposed keymanagement scheme, both a new node and group leader validates each other equally before joining the network.
Elliptic curves were independently introduced to cryptography in 1985 by Victor Miller  and Neal Koblitz . Elliptic curve cryptography (ECC) is an efficient public key cryptosystem which rely on the difficulty of discrete logarithmic problem on elliptic curves. The one of advantages of ECC is that for suitably chosen curves there is no known subexponential algorithm like the number field sieve algorithm for integer factorization, to solve the elliptic curve discrete logarithm problem. Consequently, this leads to smaller key length in ECC to achieve the same level of security as in public key systems based on factorization and the discrete logarithm problem in finite fields. Hence elliptic curves are widely applied in many aspects of cryptography including elliptic curve based protocols, data encryption and digit signature. In particular, Weil pairing and Tate pairing on elliptic curves can be utilized in identity based encryption . Further, elliptic curves can be applied in prime testing [4-5] and factoring integers .
Phosphorus in cultivated soil is one of the most important nutrient elements restricting agricultural production  , however, in recent decades, with the improving of application of phosphate fertilizer, the domestic and foreign researches show that not only does phosphorus element enrichment in cultivated soil, but the loss of phosphorus element is also serious [2, 3] . The loss of phosphorus in soil does not only waste fertilizer, but more importantly, it is also an important reason to cause the eutrophication of water body  . Researching the content and spatial variability of cultivated soil available phosphorus is the basis for adjusting the cultivation land management measures, reasonably applying phosphate fertilizer, reducing loss of phosphorus element and reducing non-point source pollution of water body [5, 6] .
decremental discount are considered. Moreover, the Stackelberg game model of both parties’ order on supply and demand is given, and examples are given for further explanation and analysis, which has a guiding significance for enterprises. The following orientations are key research orientations in the future: research on coordination order model and discrete model under multiple different retailers as well as coordination order model under multi- layer supply chain, as well as the research on supply-demand cooperation under random demand as well as coordination model under multiple retailers and multi-layer supply chain.
The literature review analysis, fuzzy AHP (FAHP) often used in group decision-making geometric shape can be obtained accurately and objectively weights. This should be quite consistent with the study of consumer intention LCD TV support analysis requirements. FAHP determined by AHP and fuzzy theory would be reviewed as follows.
Data analysis is an area of high relevance in the fields of engineering and technology, bioinformatics, medical science application, financial engineering, natural language processing and customer relationship management. Computationally intelligent method is very much needed to predict and explore optimum decision. Clustering and outlier technique is playing a significant role in computer science research and other fields. The clustering algorithm was driven by biologist Sneath and Sokal in 1963 in numerical taxonomy before being taken by the stastiscians. In many clustering methods, clusters are often determined by estimating the location and dispersion of different sample groups within a given dataset . In the literature outliers are found as a by-product of clustering algorithms that are neither a part of a cluster nor a part of the background noise; rather they are specifically points that behave very differently from
Yager’s formula shows that if the conflict evidence can’t be resolved reasonably, it should be thrown into unknown field, but it will induce another issue. Although most of evidences have proved the conclusion is right, the combination outcome would be negative. Based on Yager’s formula, Sun Quan proposed an evidence combination formula which transforms the conflict by the credibility in the literature . But this method ignores the evidence contribution to the combination outcome when computing the credibility of each group of conflict evidence.
The moving target is detected through the study of optical flow field of the image sequence in optical flow method. Optical flow field contains important information of the moving target. Optical flow is motion vector of the pixel in the image grayscale mode. The key step of the optical flow method is to obtain the optical flow information of the moving target. In the calculation of the optical flow field, the movement of the object is typically continuous in space should be taken into account. Therefore, the change of the image is continuous, so it can be assumed that the gray value of the image is not change, optical flow equation can be obtained as follows.