Group Key Regeneration for Improving Security in Spontaneous Wireless Ad hoc Networks

Abstract

Spontaneous networks are wireless ad hoc networks without fixed infrastructure and central administration. Security is the major concern in spontaneous networks because these networks will be created anywhere anytime according to user needs. Network communication is usually protected by the use of cryptography. This paper presents a security scheme which uses a hybrid cryptosystem to ensure secure communication. The scheme includes a new authentication protocol and a secure data transmission procedure. It uses public key infrastructure for authentication procedure. Initial trust establishment is based on the visual contact between users. Network traffic is protected by the use of a group key. For a node the fact of knowing the group key points out that it belongs to the network. Group key regeneration based on key use is also proposed in this paper. If the count on key use reaches the threshold value group key will be regenerated. Secure data transmission is based on the use of both public key infrastructure and symmetric key encryption. The proposed system improves the security requirements without increasing the communication cost. It also reduces the computation time and energy requirements for data encryption/decryption. The proposed system has been implemented using java programming. A security analysis of the system is also included in this paper.

Keywords: Security; Authentication; Wireless Network; Spontaneous network; public key infrastructure; symmetric encryption