Group Key Generation Scheme Based on Random Forwarding Network for Large-scale IoT Devices

The rise of the Internet of Things (IoTs) has underscored the significance of secure communication and data secret sharing. However, traditional key agreement schemes have problems such as high cost, high computing requirements, and low reliability, which are not suitable for large-scale IoT terminals. Therefore, This paper introduces a group key generation scheme based on Random Forwarding Network (RFN) to address secure communication challenges in large-scale IoT device networks. The scheme leverages the transmission delay of the RFN for group key generation, ensuring key consistency through a three-stage delay measurement protocol and information reconciliation. Additionally, the paper explores the relationship between end-to-end delay randomness and random forwarding strategy within the RFN through mathematical modeling. It presents an optimal random forwarding strategy and the maximum end-to-end delay randomness using the gradient descent method. The study also reveals that evenly distribution is the optimal distribution method for group nodes in the random forwarding route. With the support of the optimal forwarding strategy and optimal group node distribution, the scheme achieves optimal group key randomness and provides guidelines for random optimization.