Self-healing Type Key Distribution Research

One method for enabling secure communication is perodic distribution of a new key to group members. All messages exchanged within the group during a fixed interval of time ,or session are comunicated securely through encryption under this session key. In group communication especially dynamic group communication in which users join or move out frequently,an adversary can easily get information which is not entitled to .In an unreliable network ,especially in mobile wireless networks,the adversary may intentionally disrupt the wireless communication,devices are powered by batteries,it is necessary to adapt efficient key distribution scheme in term of memory storage and communication complexity.In self-healing key distribution scheme users are capable of recovering lost group keys on their own ,without requesting addition transmissions from the group manager,thus cutting back on network traffic,decreasing the load on the group manager,and reducing the risk of user explosure through traffic analysis.At first, this paper concludes previous key distribution in detail.then give the defition of self-healing key distribution.analysises some existing constructions, presents new constructions which is more efficient in term of memory storage and communication complexity. Error correction techniques is not enough for application.In previous paper, polynomial-based secret sharing technique is used to ressit packet loss.In sharing scheme, broadcast size is decided by max number of sessions and number of revoked members.In growing scheme,users recover past and future session keys using additional information from two received broadcast messages.the broadcast size grows if the session continues.In iterative scheme,session key is recovered by the iteratice of hash function only if he is a member of the group. The construction eliminated the limitation of m sessions in previous and reduce the size of broadcast size comparing to the sharing scheme and growing scheme.In sharing scheme and growing scheme,the broadcast size is big, so the network must work efficiently.In newly commmunication construction the storage overhead is (t + 1)logq,the communication overhead is ( 2t + 2+j)logq,In newly iterative construction the communication overhead is (t + 1+j)logq which is fit for wireless networks.