Unintentional forking analysis in wireless blockchain networks

The forking problem plays a key role in the security issue,which is a major concern in the blockchain system.Although many works studied the attack strategy,consensus mechanism,privacy-protecting and security performance analysis,most of them only address the intentional forking caused by a malicious attacker.In fact,without any attacker,unintentional forking still remains due to transmission delay and failure,especially in wireless network scenarios.To this end,this paper investigates the reason for generating unintentional forking and derives the forking probability expression in Wireless Blockchain Networks(WBN).Furthermore,in order to illustrate the unintentional forking on the blockchain system,the performances in terms of resource utilization rate,block generation time,and Transaction Per Second(TPS)are investigated.The numerical results show that the target difficulty of hash algorithm in generating a new block,the delay time of broadcasting,the network scale,and the transmission failure probability would affect the unintentional forking probability significantly,which can provide a reliable basis for avoiding forking to save resource consumption and improving system performance.

An Erebus Attack Detection Method Oriented to Blockchain Network Layer

Recently,the Erebus attack has proved to be a security threat to the blockchain network layer,and the existing research has faced challenges in detecting the Erebus attack on the blockchain network layer.The cloud-based active defense and one-sidedness detection strategies are the hindrances in detecting Erebus attacks.This study designs a detection approach by establishing a ReliefF_WMRmR-based two-stage feature selection algorithm and a deep learning-based multimodal classification detection model for Erebus attacks and responding to security threats to the blockchain network layer.The goal is to improve the performance of Erebus attack detection methods,by combining the traffic behavior with the routing status based on multimodal deep feature learning.The traffic behavior and routing status were first defined and used to describe the attack characteristics at diverse stages of s leak monitoring,hidden traffic overlay,and transaction identity forgery.The goal is to clarify how an Erebus attack affects the routing transfer and traffic state on the blockchain network layer.Consequently,detecting objects is expected to become more relevant and sensitive.A two-stage feature selection algorithm was designed based on ReliefF and weighted maximum relevance minimum redundancy(ReliefF_WMRmR)to alleviate the overfitting of the training model caused by redundant information and noise in multiple source features of the routing status and traffic behavior.The ReliefF algorithm was introduced to select strong correlations and highly informative features of the labeled data.According to WMRmR,a feature selection framework was defined to eliminate weakly correlated features,eliminate redundant information,and reduce the detection overhead of the model.A multimodal deep learning model was constructed based on the multilayer perceptron(MLP)to settle the high false alarm rates incurred by multisource data.Using this model,isolated inputs and deep learning were conducted on the selected routing status and traffic behavior.Redundant intermodal information was removed because of the complementarity of the multimodal network,which was followed by feature fusion and output feature representation to boost classification detection precision.The experimental results demonstrate that the proposed method can detect features,such as traffic data,at key link nodes and route messages in a real blockchain network environment.Additionally,the model can detect Erebus attacks effectively.This study provides novelty to the existing Erebus attack detection by increasing the accuracy detection by 1.05%,the recall rate by 2.01%,and the F1-score by 2.43%.

A Public Blockchain Consensus Mechanism for Fault-Tolerant Distributed Computing in LEO Satellite Communications

In LEO(Low Earth Orbit)satellite communication systems,the satellite network is made up of a large number of satellites,the dynamically changing network environment affects the results of distributed computing.In order to improve the fault tolerance rate,a novel public blockchain consensus mechanism that applies a distributed computing architecture in a public network is proposed.Redundant calculation of blockchain ensures the credibility of the results;and the transactions with calculation results of a task are stored distributed in sequence in Directed Acyclic Graphs(DAG).The transactions issued by nodes are connected to form a net.The net can quickly provide node reputation evaluation that does not rely on third parties.Simulations show that our proposed blockchain has the following advantages:1.The task processing speed of the blockchain can be close to that of the fastest node in the entire blockchain;2.When the tasks’arrival time intervals and demanded working nodes(WNs)meet certain conditions,the network can tolerate more than 50%of malicious devices;3.No matter the number of nodes in the blockchain is increased or reduced,the network can keep robustness by adjusting the task’s arrival time interval and demanded WNs.