Generalized self-healing key distribution in wireless adhoc networks with trade-offs in user's pre-arranged life cycle and collusion resistance

Abstract

Self-healing key distribution deals with the problem of distributing session keys for secure communication to a dynamic group of users over an unreliable, lossy network in a manner that is resistant to packet lost and collusion attacks. Self-healing property enables a user who has been off-line for some period to recover the lost session keys immediately after coming back on-line. We introduce the collusion resistance property in a generalized self-healing key distribution proposed by Dutta et al. with a trade-off of pre-arranged life cycle on authorized users and a slight increase in storage, the approach of Tian et al.. Our setup therefore allows each user to choose its joining session at its will, but the session for its revocation is pre-selected by the group manager. Several innovative business models allow contractual subscription or rental by the service provider for the scalability of business and do not allow the user to revoke before its contract is terminated. Our scheme is suitable for such applications. The proposed scheme provides better efficiency in communication and storage as compared to the existing approaches besides achieving collusion resistance property. Our construction is properly analyzed in an appropriate security model and is proven to be computationally secure and achieve both forward and backward secrecy. Moreover, rejoining of revoked users can be done in our scheme at later sessions with new identities without compromising security, unlike the existing self-healing schemes.