Question

Solve the following:

There are 7 nodes, N1 to N7. N1 and N3 are Byzantine faulty nodes. Use OM(2) to solve this problem. N1 is the initial commander. Assume it sends a 0 to N2, N3, and N4 and it sends a 1 to N5,N6, and N7. You can choose any values for N3 to send to its receivers. Show the message sending tree and compute the output of the non faulty nodes

Answer 1

The aim of Cluster based model to maintain trust relationship dynamically and efficiently in MANET. . In this model, ad-hoc network divided into clusters. Important terms used in this model, 1. Direct trust value: - any two nodes in cluster calculate trust value between them according to recent transaction records.

Inter cluster trust value: - Cluster head collected the recommendation information from other nodes to compute the inter cluster trust value.

Gateway: - It maintains interaction between MANET’s node with adjacent cluster.

4. Routing:-Two type of cluster routing is used in this model. One is Intra-cluster routing, the routing with in a cluster. Another is Inter-cluster routing, the routing between two different clusters. Zone routing protocol is used in cluster based model, which is combination of “Proactive” (intra-cluster routing) and "Reactive” (inter-cluster routing).

(A)Direct trust Representation & its computation [14, 15, 16] From Node N, to N, direct trust represented as TRO calculation of direct TRD 120, a > 0 In case, when there is no previous interaction between mode N and N t is the time transactions, tn is time success and a is a positive real number. a is inversely proportional to evidence in this model.

(B) Intercluster Recommendation Trust value's Representation & its calculation It is denoted as TR and calculated as: iEl TR, is aggregation weight (direct trust value of node Ni computed by CH). TR", is direct trust ons information and n is the number of nodes in current cluster. N7 N5 i N2 CH2 N8 CHI N6 N3 N9 N4 Figure 2. Cluster Based Trust Model in MANET

Intermational Journal on AdHoc Networking Systems (UANS) Vol. 2, No. 2, April 2012 GATEWAY MANETS NODE (C) Total trust representation & computation It is represented as r(N N) and computed as: where α, β 20 and α + β-1. TR% is the direct trust between nodes N, and N, α is the impact weight of direct trust and B is the impact weight of recommendation trust. wh di e d N, a is npet (D) Cross cluster trust: The cross cluster trust between nodes N3 & N7 can be calculated as: r(N3, N7)-r(N3, N6). Г (N6, N7) 4) N3 node is in cluster cl and N7 is in c2, through node N6 (gateway) both nodes are connected. r(N3, N6) is the global trust of node N6 by node N3.This trust value is calculated in cl because node N3 and N6 locates in c1. r(N6, N7) is global trust, which calculates in cluster c2 because node N6 and N7 comes in cluster c2. Merits of cluster based trust model: No need of personal or past experience of any node in MANET for evaluation of trust value on nodes. Effective work in a small scale Ad-hoc network, Cluster head (CH) and gateways used in this model. There is no need of centralized infrastructure. Demerits: The performances will be degraded when cluster based model used in larger size MANET.