Research Paper Summary-Engg. Branch (CS)

Title: A Fault Tolerant, Secure and Distributed Group Key Diffie Hellman Key  

             Exchange Protocol for Mobile Adhoc Networks

          National conference on “Advances in Computer Networks and Information Technology (NCANIT)”

1.   Abstract

      A mobile adhoc network (MANET) is a Multi hop wireless network capable of autonomous operation and requiring no infrastructural support. The purpose of an adhoc network is to set up possibly a short lived network for a collection of nodes. Security in mobile adhoc networks is difficult to achieve notably because of vulnerability of wirelees links, limited physical protection of nodes, dynamically changing topology, absence of certification authority and lack of centralized monitoring or management point.

                    In this paper they present, design and implementation of a A Fault

Tolerant, Secure and Distributed Group Key Diffie Hellman (FASED-GDH) Key    Exchange Protocol which is a n-party generalization of the basic two party Diffie-Hellman Protocol for key exchange. FASED-GDH is a ring based protocol in which each peer contribute its partial factor for the final establishment of secure session key. The protocol provides a secure multicast of pseudo final key leading to an inbuilt intrusion detection system. The protocol is simple as compared to previous approaches. Failure of a subset of nodes leaves the system unaffected, thereby proving its robustness and fault tolerance.

2.   Introduction

Group Key Diffie Hellman protocol provides both the things: it uses public key technique to allow the exchange of a private encryption key. It is an Authenticated Key Exchange protocol which is designed to provide a pool of players with a shared secret key which may later be used. For example: to achieve multicast message integrity.Over the years the several schemes have been proposed. However no formal treatment for cryptographic problem is suggested. In this paper, they present a security model, FASED-GDH, for this problem and use it to precisely define AKE as the fundamental goal. In AKE, each player is assured that no other player aside from the arbitrary pool of players can learn any information about the session key.They then define in this model the execution of an authenticated group Diffie-Hellman scheme and prove its security.

3.   System Model

In FASED-GDH they have assumed a session of adhoc network which consist of a collection of nodes or peers that need a secret secure session key to start the communication. The system design for this establishment of key is as follows:

Each peer can act as both client and server. Any peer who wants to start the communication named Init Server sends its contribution to its neighbor, the neighbor add its contribution and then sends the combined result to its neighbor.

This process goes on till the final establishment of key. Now the destination server will not send this final key to remaining peers instead it send their partial factor to the corresponding peers which then further add their own private factor for the final establishment of key.