Indian Institute of Management Calcutta

About: Indian Institute of Management Calcutta is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Supply chain & Context (language use). The organization has 415 authors who have published 1354 publications receiving 21725 citations. The organization is also known as: IIMC & IIM Calcutta.

Achieving Correctness in Fair Rational Secret Sharing

Abstract: In rational secret sharing, parties may prefer to mislead others in believing a wrong secret as the correct one over everybody obtaining the secret (i.e. a fair outcome). Prior rational secret reconstruction protocols for non-simultaneous channel only address the case where a fair outcome is preferred over misleading and hence are fair but not correct. Asharov and Lindell (2010) proposed the first and the only protocol that takes care of both the preferences. In this paper, we propose a new rational secret sharing protocol that addresses both the preferences and is fair and correct in the non-simultaneous channel model. Additionally, it is independent of the utility of misleading. Each rational party is given a list of sub-shares of shares of the actual secret and fake shares. In each round of the protocol each party sends the current element in its list to the other party and then reconstructs a share from the sub-shares obtained. The main idea is to use a checking share which is a share of the original secret as a protocol—induced membership auxiliary information to check whether the shares obtained till a certain round can be used to reconstruct the correct secret. We overcome the disadvantages of the presence of auxiliary information by using the time-delayed encryption scheme used by the protocol of Lysyanskaya and Segal (2010) that tolerates players with arbitrary side information. In our case, the side information used is not arbitrary but introduced by the mechanism/protocol designer to put all players on equal footing. We show that our protocol is in computational strict Nash equilibrium in the presence of protocol-induced auxiliary information.

The Changing Rural-agrarian Dominance: A Conceptual Excursus:

Abstract: Based on a review of extant literature, this article entreats for thorough-going empirical investigation of rural-agrarian dominance in the context of the fundamental transformation of the ‘village...

A systems view of the measurement of the performance of public enterprises in India

Abstract: This article presents systems approach to the measurement of the performance of public enterprises in India. Thus it is a movement from a narrow concept of efficiency to a broader approach wherein measurement of performance is linked to the achievement of objectives. The need for such an approach is based on the theoretical developments and set against the problems currently experienced by public enterprises in India. As an alternative a three-tier objective framework, with standards, and a set of agencies for evaluation is recommended. Finally the problems of application of the three-tier objectives are discussed.

Average-case analysis of heuristic search in tree-like networks

Abstract: A search graph has the form of an m-ary tree with bi-directional arcs of unit cost. There is a goal node at a distance N from the root, and there may be other goal nodes at distances ≥ N from the root. It is assumed that the heuristic estimates of nongoal nodes, after being appropriately normalized, are independent and identically distributed random variables. The heuristic is not required to be admissible. Under what conditions is the expected number of node expansions E(Z) polynomial in N? Earlier efforts by Pearl and others at answering this question have considered search trees with only one goal node. An attempt is made here to develop a general and unified method of analysis applicable to situations with more than one goal node. It is shown that, for most probability distributions on the heuristic estimates, E(Z) is exponential in N; the one major exception being the case when the number of goal nodes is polynomial in N and the normalizing function for the error is logarithmic. Pearl’s contention that the average-case analysis of weighted heuristic search is not too attractive is also verified. It is hoped that the general approach described here will encourage similar studies on search graphs other than trees.

Pharmaceutical Prices in India

Abstract: The contribution of India in making patented drugs more affordable has been recognised widely. Though the prices of patented drugs are lower in India, the retail markets suffer from several imperfections. As a result, despite the existence of large number of manufacturers, substantial price differences exist between different brands of the same drug. In India medicines are purchased mainly by the people themselves rather than by the government or through health insurance. Because of limited public health and insurance facilities, access to medicines has been low in India. India has drug price control in some form or the other since 1963. But India adopted a selective approach—while some drugs are under control, competing drugs have been kept out of control. This provided the opportunity to manufacturers to stop or reduce the manufacture and sale of drugs under control and promote the competing ones out of control. After 2005, India has re-introduced product patent protection. MNCs have started selling new patented drugs at exorbitant prices but these are yet to be included under price control. India has been able to restrict product patents by exempting grant of patents under certain conditions. But potentially the more effective instrument of compulsory licensing has remained unutilized in India.