SMOCK: A Scalable Method of Cryptographic Key Management For Mission-Critical Networks

Abstract — Mission-critical networks show great potential in emergency response and/or recovery, health care, critical infras-tructure monitoring, etc. Such mission-critical applications de-mand security service be “anywhere”, “anytime ” and “anyhow”. However, it is challenging to design a key management scheme in current mission-critical networks to fulfill the required attributes of secure communications, such as data integrity, authentication, confidentiality, non-repudiation and service availability. In this paper, we present a self-contained public key management scheme, called SMOCK, which achieves almost zero commu-nication overhead for authentication, and offers high service availability. In our scheme, small number of cryptographic keys are stored off-line at individual nodes before they are deployed in the network. To provide good scalability in terms of number of nodes and storage space, we utilize a combinatorial design of public-private key pairs, which means nodes combine more than one key pair to encrypt and decrypt messages. We also show that SMOCK provides controllable resilience when malicious nodes compromise a limited number of nodes before key revocation and renewal. I