Blockchain-Based Privacy Protection Scheme For Medical And Health Big Data

Blockchain is a novel data management tool with the characteristics of decentralization and transparency,which can effectively reduce the cost of data storage and data access.However,different from the ordinary data,medical data is frequently updated and involves privacy.Hence,it is not suitable to use ordinary blockchain to manage the medical data directly,otherwise it will bring great communication overhead and the risk of privacy disclosure.In view of the above problems,this paper will introduce a blockchain-based medical data management scheme form the perspectives of medical data storage and sharing.Specifically,this paper does the following work:(1)A chameleon hash scheme with changeable trapdoor is proposed in this paper.Most of the existing schemes use fixed trapdoors,which have the problems of trapdoor exposure and abusement.The scheme proposed in this paper adds a variety of constraints to the use and update of trapdoors,which can effectively prevent trapdoors from being abused.After giving a detailed security proof,this paper tests the performance of the scheme.Experimental results show that the new scheme has lower computational overhead and is compatible with the underlying hash algorithm.(2)A traceable ring signcryption scheme is proposed in this paper.The traditional signcryption scheme can realize the functions of digital signature and encryption in a single logical step,but it lacks privacy protection for the signcryption sender.The scheme proposed in this paper can hide the identity of the signcryption sender,and trace the source of the signcryption when necessary.After providing a detailed security proof,the performance analysis of the proposed scheme is given.Experimental results show that the proposed scheme meets more security requirements and has lower computational overhead.(3)A blockchain-based medical data management scheme is proposed.This scheme utilizes the characteristics of redactable blockchain and ring signcryption,and pays particular attention to the security and privacy protection issues in medical data management.Combined with the actual medical data storage and sharing scenario,this paper introduces the application process of the scheme in detail,and designs a medical data management system based on the proposed scheme.