Research On Access Control In Smart Grid Cloud Storage System

Smart grid has become a major trend in the development of power systems.One important point that distinguishes the smart grid from traditional grids is the presence of a large number of sensors in the smart grid,forming many wireless sensor networks.In addition,because there are massive heterogeneous data to be dealt with in the smart grid,the smart grid combines with the cloud storage system to form a power cloud system.In recent years,scholars at home and abroad have conducted extensive research on access control problems in smart grid wireless sensor networks and cloud storage systems.These reserch have reached a lot of achivements.However,there are still some problems that need further study.For example,for nodes in a wireless sensor network,public key encryption algorithm means a large overhead.Attribute-based access control schemes in smart grid cloud storage systems usually need complicated encryption and decryption operations and take high computational costs.To solve these problems,we designs schemes to improve the efficiency with consideration of the access control requirements in the smart grid system.This thesis mainly completed the following work:1.This thesis analyzes the access control requirements in the wireless sensor network of smart grid in a certain area,and designs an access control scheme based on Bloom filter.The scheme uses Bloom Filter for authentication between nodes.Only those nodes passing the authentication phase can complete key exchange and access control operation through the elliptic key exchange protocol.A node that has not finished authentication cannot continue its access request.This avoids running expensive algorithms for illegal users.2.For the access control requirements in smart grid cloud storage systems,a cloud storage system model with data access rights outsourcing is designed.In this system model,data is encrypted and uploaded to cloud storage servers.Because cloud storage servers are semitrusted,users cannot fully trust cloud servers.For the purpose of privacy protection,data access authority is responsible for data access.The Data Access Authority verifies the rights of the data visitor and decides whether to authorize it.3.Based on the cloud storage system model of outsourcing data access model designed in this thesis,this thesis presents a smart grid cloud access control scheme based on privacy-preserving scalar product computation(PPSPC).In this scheme,the user's permission set is represented by a vector of attributes.Only when the number of identical attributes between two parties reaches the threshold value,the user can obtain authorization.The PPSPC protocol masks the calculation process using random numbers in the calculation process and generates intermediate vector sets.Then,next calculations are based on the intermediate vector set to achieve the purpose of privacy protection.Finally,we analyze the safety of the proposed schemes and choose several typical schemes to compare with the proposed ones.Through simulation experiments and comparative analysis,it shows that the proposed schemes have high efficiency and feasibility.