Investigation On Medical Data Sharing Mechanism Based On Blockchain

With the continuous development and popularization of cloud computing and big data,electronic medical system will be widely used in medical institutions.With the rapid growth of medical data,how to share medical data on the premise of ensuring the privacy and security of data holders and medical data has become an urgent problem to be solved in the electronic medical system.In this thesis,medical data is divided into smaller medical data such as health indicators that need to be monitored every day and larger medical data such as electronic medical records and electronic images.This thesis studies the sharing mechanism of medical data based on blockchain,Two security sharing schemes are adopted to realize the security sharing of small-scale medical data and large-scale medical data respectively.The main research contents of this thesis are as follows:（1）When the medical data to be shared is daily health index data,this thesis proposes a small-scale medical data security sharing scheme based on blockchain.This scheme records the keyword information and sharing process of medical data based on blockchain.Firstly,the zero knowledge proof mechanism is used to verify whether the medical data keyword information held by the data holder is consistent with the medical data keyword information released by the medical research institution,so as to verify whether the medical data of the data holder meets the needs of the medical research institution.After passing the verification,the medical data sharing system is used to verify the identity information of data holders and data receivers and the security of data sharing environment.After successful verification,the homomorphic encryption algorithm will be used to encrypt the medical data,and the homomorphic addition operation will be used to verify whether the daily health index value of the data holder is within the reasonable range issued by the medical research institution.Finally,the data conversion operation will be carried out on the output result set to protect the privacy information of the data holder.（2）When the medical data to be shared are electronic medical records and electronic images,this thesis proposes a large-scale medical data security sharing scheme based on blockchain.This scheme records the summary information and sharing process of medical data based on blockchain,and then the data holder will encrypt and upload the medical data to the distributed cloud storage platform.At the same time,the medical data sharing system is used to verify the identity information of the data holder and data receiver and the security of the data sharing environment.After passing the verification,the proxy re-encryption algorithm will be used to re encrypt the ciphertext of the medical data,and the re-encrypted ciphertext will be transmitted to the medical mechanism,so as to realize the safe sharing of large-scale medical data.（3）The medical data sharing system is designed and implemented to improve the security of medical data sharing by verifying the identity of login users and detecting the security of sharing environment.（4）The distributed cloud storage platform system is designed and implemented to ensure the authenticity and integrity of medical data,and the privacy of medical data of data holders is guaranteed by dividing user permissions.Theoretical analysis shows that the scheme proposed in this thesis can meet the security requirements of confidentiality,integrity and availability.At the same time,it can ensure the privacy of data holders and the security of medical data,and realize the operability of ciphertext.The experimental results show that the scheme proposed in this thesis is available and efficient.