Research On Blockchain Access Control Technology Based On Ciphertext-Policy Attributes Based Encryption

With the continuous development of the Internet of Things,the problem of information security has attracted high attention.Access control,as a key technology of secure data sharing,is a means to protect data from being used and accessed by unauthorized users.However,the traditional access control mechanism mostly adopts centralized trusted service decision entity model,which easily leads to data monopoly and security risks.In addition,in the face of large and complex Internet of Things systems,the traditional access control mechanism is difficult to meet the mass heterogeneous,dynamic and distributed computing environment.Therefore,it is necessary to design a more reliable,flexible and dynamic fine-grained access control mechanism to protect data confidentiality,integrity and availability.As an emerging integration technology,blockchain can establish trusted data access control between individuals or organizations in weak or no trust networks due to its characteristics of data rights confirmation,imtamability and consensus synchronization.Therefore,it is an effective and reasonable choice to improve the robustness and anti-attack capability of data access control in the Internet of Things environment by integrating blockchain technology.Based on the user's identity and attributes,this paper studies the block chain access control technology based on ciphertext attributes from the aspects of model and encryption,and proposes an Internet of Things access control model based on ciphertext attributes and block chain.The simulation results show that the proposed scheme has better performance while being secure and efficient,and is more suitable for the data sharing requirements of distributed and large-scale equipment resources in the Internet of Things environment.The specific research contents and innovations are as follows:1.Access control model: proposed an identity-and attribute-based block chain data access control model IAPBCAC.This article embarks from the actual block chain,in a distributed public key infrastructure on the basis of introducing the user id and entity attributes element,use the interaction between the organization and user authorization,endorsed identity attribute links trust realization cost,solve the traditional access control model cannot satisfy the distributed environment,and the massive user access to huge amounts of data control the inflexible problem.2.Encryption mechanism: a distributed attribute base encryption scheme CP-IAPBE based on "identity-attribute" paired authentication is proposed.First of all,based on the attribute based encryption cipher strategy(CP-ABE)scheme and design a distributed key calculated based on user identity based on zero knowledge proof and correctness consensus verification method,key to consensus network ACTS as a trusted entity,solved the CP-ABE in calculation caused by relying on the central trusted entities,and such problems as high cost of trust and a single point of failure;In addition,this paper also proposes an extension scheme to support outsourcing decryption,which effectively reduces the user's decryption cost.