Study On Semantic And Ciphertext-policy Attribute-Based Encryption Technology For Access-Control In Medical Cloud

With the improvement of medical information sharing and the maturity of cloud storage technology,the scale of medical cloud market is also expanding.While the sharing of information by medical cloud storage undoubtedly provides convenience to users,the security of data is of particular importance because the user's medical data is mostly sensitive and involves the privacy of the individual.To ensure data security,encryption and access control are usually required to ensure that data is not illegally stolen.However.most traditional access control models are centralized role-based rights management.Allocation of permissions is entirely performed by the system administrators.In a cloud environment,which is distributed and hosted by a third-party,such access control models are not fine-grained enough and permissions are not flexible.Therefore,this paper designs and implements a flexible and decentralized asymmetric encryption-based access control scheme by using the semantic technology and the ciphertext-policy attribute-based encryption algorithm.In this paper,ciphertext-policy attribute-based encryption is used as the basic method of data encryption and encrypted access control.At the same time,the semantic technology is introduced.The access policy attribute knowledge base is designed through the process of knowledge acquisition,knowledge extraction and knowledge expression,and an ontology model was constructed.On the one hand,in the process of user encryption,automation of rights control is achieved through the automatic extraction,management,pushing and application of encryption policy attributes.On the other hand,it benefits from the standardization of ontology and improves the sharability and consistency of the encryption system.Moreover.it further considers the safety of medical services in addition to improving the efficiency and flexibility of data security protection.In case of first aid in medical treatment,semantic reasoning can be conducted according to the rules.In accordance with the basic principle that the user's life right is greater than the right of privacy,access privileges should be urgently opened to medical and nursing staff so as to save the patient's life and improve clinical safety.