An Improved Outlier Detection Mechanism for Hierarchical Key Management in Hierarchical Mobile Ad-hoc Networks (MANETs)

The purpose of this paper is to present an outlier detection mechanism for hierarchical key management which utilizes hybrid (public and private) key management scheme for implementing lightweight cryptographic primitives in hierarchical MANETs. Further, a comparative analysis of key management schemes is to be performed for identifying an efficient key management scheme for hierarchical MANETs. In key management methods, public and private group key management schemes are integrated at local level (subgroup) and global level (network). These key management schemes uses various topologies for minimizing communicational and computational costs. After implementing an efficient key management scheme, outliers in network are identified using packet analysis at key generation, key distribution, message transmission and key re-generation phases. It is observed that Teo and Tan key management approach with shamir’s threshold key distribution mechanism is an efficient approach key management scheme for group authentication and hierarchical key management. Further, a minimum improvement of 9.7% and 0.91%, and maximum improvements of 25.3% and 87.7% are observed for Packet Delivery Rate (APDR) and Average Throughput (AT) respectively in a network of 1000 nodes. The proposed method requires four sequential analysis of outlier detection schemes at different layers of MANET protocol stack because single scheme per layer is not efficient in identifying outliers in proposed network. The proposed key management method is useful for MANETs in group authentication and implementation of lightweight cryptographic primitives with secure key. Further, outlier detection mechanism can be extended for identifying various active and passive attacks.