Design And Implementation Of Data Controllable Access System Based On Blockchain

Access control technology is a defensive measure against data unauthorized access or resources usage.However the existing access control policy has a complicated access decision process and is polarized to access authorization,which is prone to over-authorization or insufficient authorization.This paper aims to simplify the access decision process and solving the problem of over-authorization and insufficient authorization with the help of blockchain,and designs and implements a data controllable access system based on blockchain.In the data controllable access system designed in this paper,aiming at solving the complex problem of access decision-making process,the smart contract is used in the blockchain to implement the RBAC(Role-Based Access Control)strategy to assign roles to users to authorize data access,then learning from Pau-Chen Cheng's risk assessment idea,based on system's Trust value coded Uc(User Credit)and data sensitivity coded Ds(Data Sensitivity)and the risk threshold assigned to the user ' s role,a risk assessment algorithm is used to intercept low-credit users' access to highly sensitive data.Through a two-step control strategy of static authorization and dynamic interception,it is convenient for authorized users to access data while intercepting access to highly sensitive data by users with low credit values belonging to the same role,so as to simplify the decision-making process,and realize controlled access to data.As for the problem of over-authorization and insufficient authorization,the operation related to access authorization and access request shall be recorded in the blockchain,we can check whether the user is granted a suitable range of data access by traversing the records in the blockchain based on its non-tamperable characteristics through comparing the authorization records and user request records,and urge the managers of the access control system to authorize reasonably.This paper deeply investigates the development status of the data access field and blockchain technology.And then it introduces a risk assessment algorithm to evaluates the risks caused by'user access requests to the system.Next it conducts a requirement analysis concerning the data controllable access system to determine the functional and performance requirements.Then describe the overall design of the system,and analyze several key issues faced in the implementation process and proposes corresponding solutions.Then describe the design and implementation of each module of the system in detail,and finally test the system.At the end of the paper,the author's work is summarized,and some personal opinions are put forward on the shortcomings of this system and the expectations of the next stage of work.