Research On Rational Assessment Model And Application Of Blockchain Privacy Leakage Ris

The diversification and complexity of data information make the security and efficiency of blockchain technology face huge challenges,including the issue of privacy leakage risk for blockchain systems.This thesis focuses on the existing blockchain privacy leakage risk and rational assessment,The following three aspects are mainly raised:1.A risk assessment model of blockchain privacy leakage based on offensive and defensive game.First of all,Aiming at how to assess the privacy leakage risk of blockchain systems,this thesis analyzes each technical architecture layer of blockchain and quantify the costs and benefits to attackers through an offensive and defensive game-based approach,so as to investigates the privacy leakage risk of the blockchain.Secondly,the user sensitivity matrix is constructed based on the different sensitivity of users to each attack in the blockchain technical architecture layer,and the subjective sensitivity and objective sensitivity are calculated respectively.Finally,a static Bayesian game(II-SBGM)with asymmetric information is constructed by strategic interaction between honest users and malicious attackers of blockchain,and the existence of Nash equilibria are proved.The feasibility and effectiveness of this method are verified by simulation.2.A blockchain privacy leakage risk assessment model based on improved Paillier algorithm.Firstly,in view of data privacy protection,a blockchain privacy leakage risk assessment model based on the improved Paillier algorithm was established by combining homomorphic encryption algorithm.Secondly,nodes classification is set to store transaction data.Nodes are divided into four levels: top secret,confidential,secret and public.Nodes of different levels process privacy data of corresponding levels to ensure that data hierarchical management achieves privacy protection to a certain extent.Finally,by comparing the experimental data,it is proved that the improved Paillier algorithm and node classification have a certain privacy protection effect on the risk of blockchain privacy leakage.3.Application scenarios of blockchain privacy leakage risk rational assessment model.The above model is implemented by Python and verified by medical data.The effectiveness and feasibility of the method are proved by comparing and evaluating the data privacy and security before and after homomorphic encryption,Ensuring the feasibility of the scheme,this thesis proposes a rational risk assessment model for blockchain privacy leakage,and combines with practical application scenarios,makes a contribution to solving the problem of blockchain privacy leakage.