A Lightweight and Attack Resistant Authenticated Routing Protocol for Mobile Adhoc Networks

In mobile ad hoc networks, by attacking the corresponding routing protocol, an attacker can easily disturb the operations of the network. For ad hoc networks, till now many secured routing protocols have been proposed which contains some disadvantages. Therefore security in ad hoc networks is a controversial area till now. In this paper, we proposed a Lightweight and Attack Resistant Authenticated Routing Protocol (LARARP) for mobile ad hoc networks. For the route discovery attacks in MANET routing protocols, our protocol gives an effective security. It supports the node to drop the invalid packets earlier by detecting the malicious nodes quickly by verifying the digital signatures of all the intermediate nodes. It punishes the misbehaving nodes by decrementing a credit counter and rewards the well behaving nodes by incrementing the credit counter. Thus it prevents uncompromised nodes from attacking the routes with malicious or compromised nodes. It is also used to prevent the denial-of-service (DoS) attacks. The efficiency and effectiveness of LARARP are verified through the detailed simulation studies.Comment: 14 Pages, IJWM

The Transformation of Microfinance in India: Experiences, Options and Future

The paper looks at the growth and transformation of microfinance organisations (MFO) in India. We first, define microfinance and identify its "value attributes". Having chosen only those MFOs that have microfinance as the core, we look at the transformation experiences. To understand the transformation experiences better, we identify issues that trigger transformation viz: size, diversity of services, financial sustainability, focus and taxation. Having identified these we look at transformation experiences internationally. We examine the Bolivian, Kenyan, Bangladeshi and the Indonesian experience. We then look at the Indian experiences. We argue that the transformation experiences in India are not large in number. However, we have found that there are three forms of organisations that seem to be popular in the microfinance sector - the Non-Banking Finance Companies, the Banks - both Local Area Banks and Urban Co-operative Banks and the Co-operatives. We then argue that in the Indian case, we find that the MFO spins off from the NGO rather than the NGO transforming itself. Having examined various options, we conclude that there is no ideal or easy path for MFOs to mainstream in India. This has implications for regulatory framework. We argue that there should be regulatory changes that allow smaller MFOs to get into more complex forms as they grow organically. We also argue that NGOs should be allowed to invest in the equity of MFOs and MFO promoted banks, as is the case in Bolivia and Africa. We maintain that entry norms on capitalisation for the current forms of organisations (NBFCs, Co-ops and Banks) need not be changed to ensure only genuine MFOs make use of the legislation and not other organisations masquerading as MFOs.

On the limit matrix obtained in the homogenization of an optimal control problem

A new formulation for the limit matrix occurring in the cost functional of an optimal control problem on homogenization is obtained. It is used to obtain an upper bound for this matrix (in the sense of positive definite matrices)

Exact Tagged Particle Correlations in the Random Average Process

We study analytically the correlations between the positions of tagged particles in the random average process, an interacting particle system in one dimension. We show that in the steady state the mean squared auto-fluctuation of a tracer particle grows subdiffusively as $sigma^2(t) ~ t^{1/2}$ for large time t in the absence of external bias, but grows diffusively $sigma^2(t) ~ t$ in the presence of a nonzero bias. The prefactors of the subdiffusive and diffusive growths as well as the universal scaling function describing the crossover between them are computed exactly. We also compute $sigma_r^2(t)$, the mean squared fluctuation in the position difference of two tagged particles separated by a fixed tag shift r in the steady state and show that the external bias has a dramatic effect in the time dependence of $sigma_r^2(t)$. For fixed r, $sigma_r^2(t)$ increases monotonically with t in absence of bias but has a non-monotonic dependence on t in presence of bias. Similarities and differences with the simple exclusion process are also discussed.Comment: 10 pages, 2 figures, revte

Condensation and Clustering in the Driven Pair Exclusion Process

We investigate particle condensation in a driven pair exclusion process on one- and two- dimensional lattices under the periodic boundary condition. The model describes a biased hopping of particles subject to a pair exclusion constraint that each particle cannot stay at a same site with its pre-assigned partner. The pair exclusion causes a mesoscopic condensation characterized by the scaling of the condensate size $m_{\rm con}\sim N^\beta$ and the number of condensates $N_{\rm con}\sim N^\alpha$ with the total number of sites $N$. Those condensates are distributed randomly without hopping bias. We find that the hopping bias generates a spatial correlation among condensates so that a cluster of condensates appears. Especially, the cluster has an anisotropic shape in the two-dimensional system. The mesoscopic condensation and the clustering are studied by means of numerical simulations.Comment: 4 pages, 5 figure

Effect of spatial bias on the nonequilibrium phase transition in a system of coagulating and fragmenting particles

We examine the effect of spatial bias on a nonequilibrium system in which masses on a lattice evolve through the elementary moves of diffusion, coagulation and fragmentation. When there is no preferred directionality in the motion of the masses, the model is known to exhibit a nonequilibrium phase transition between two different types of steady states, in all dimensions. We show analytically that introducing a preferred direction in the motion of the masses inhibits the occurrence of the phase transition in one dimension, in the thermodynamic limit. A finite size system, however, continues to show a signature of the original transition, and we characterize the finite size scaling implications of this. Our analysis is supported by numerical simulations. In two dimensions, bias is shown to be irrelevant.Comment: 7 pages, 7 figures, revte