Research On Safety Quantification Theory Of Vehicular Ad Hoc Networks

Vehicular Ad Hoc Network(VANETs)is the application of Mobile Ad Hoc Network(MANET)in the field of transportation,and it is also an important role in the future Intelligent Traffic System(ITS)status.In recent years,with the development of the automotive industry and the arrival of the 5G era,VANETs has gradually entered people's horizons.Although the emergence of VANETs enables people to better control the vehicle and the surrounding environment in terms of assisting driving,safety warning and vehicle control,and avoids many traffic accidents,the subsequent safety issues are gradually highlighted come out.For example: an attacker can forge false data information in VANETs open network environment,causing traffic accidents;remotely controlling vehicles,threatening people's lives;tampering with data information,publishing wrong information to other vehicles,and causing social traffic chaos Wait.VANETs do not have a fixed infrastructure,but rely on the vehicle itself to provide network functions.Therefore,as the vehicle moves,environmental factors such as the number of eavesdropping nodes around it,security strength,and time delay are constantly changing,so the security status of VANETs is also constantly changing.At the same time,the information dissemination of VANETs is in an open access environment,so when a vehicle node sends out information,all vehicle nodes with communication capabilities within the communication range will receive the information,which undoubtedly makes some Malicious attack nodes have an opportunity.The work of this article is divided into two parts.One is to determine the current state of VANETs and to achieve quantification of VANETs safety.The second is to propose the HDTMC state transition model,introduce the division of VANETs into 7 states,and describe the transition between states caused by event triggering between states.The third is to calculate the transition probabilities of the VANETs in the current state through the Markov chain calculation,which can help the VANET security mechanism and return the VANETs to a safe state as soon as possible.First,this paper divides the HCTMC state model into 7 states to make it correspond to the 7 states of VANETs.Second,it proposes a safety state determination function to determine the state of VANETs according to the safety intensity and delay in the current environment.Use encryption strength as a measure of security strength.Finally,using the HDTMC state transition model,the Homogeneous Continuous-Time Markov Chain(HCTMC)is split into a Homogeneous Discrete-Time Markov Chain(HDTMC)and The Homogeneous Poisson Process(HPP)performs state-to-state transitions and obtains the probability of the current state transitioning to each state.In order to realize the work in this paper,the current strength of VANETs is determined by the three-dimensional image of function T with security intensity and delay,and the probability of HDTMC state transition is analyzed using the transmission power,packet transmission probability,and data frame length.The experimental results show that the safety state determination function and HDTMC state transition model proposed in this paper can dynamically determine the current state according to environmental factors and quantify the safety level in real time;the state transition probability calculated by the calculation can be the security defense mechanism of VANETs Provide effective help.