A provably secure sharding based blockchain smart contract centric hierarchical group key agreement for large wireless ad‐hoc networks

Abstract

Summary Group key management with privacy preserving and trust still remains a precarious and stimulating issue for securing multicast communications in an energy embarrassed large wireless ad‐hoc networks (WANETs). To address this, few researchers with the adaption of blockchain technology and practical usage of a privacy‐preserving smart contract as group controller made these group key agreements adaptable to WANET. However, proportionate to the increase in the size of the group, the processing load on the smart contract is also increasing, which made the capability of the smart contract could not work beyond a certain group size. Contemporary blockchain schemes suffer from various inherent shortcomings in their latency, scalability, and processing throughput. So, in this direction, we adopted blockchain sharding smart contract‐centric processing for making the key agreement adaptable to large WANETs. In this technique, we divide the large network into r sharded subnetworks with G 1 , G 2 , G 3 , …, G r as smart contract instances generated by group controller G , which acts as subgroup controllers to their respective shards using blockchain sharding technique. This protocol is shown secure under the assumptions elliptic curve decision Diffie–Hellman and group‐elliptic curve Diffie–Hellman. The performance analysis demonstrates that the proposed protocol is highly proficient than examined protocols for secure communication in large WANETs.