Research On Efficient Policy Hidden Attribute Encryption In Smart Health

In recent years,Smart Health Systems based on Io T technology have been developed extensively.In Smart Health Systems,a large amount of patients’ personal data as well as medical information is outsourced to be stored in the cloud.However,these cloud storage systems are managed by third-party cloud service providers(CSPs)and are at risk of data leakage if the data is uploaded directly to the cloud in plaintext.Ciphertext Policy Attribute Based Encryption(CP-ABE)technology,which supports fine-grained access control and protects data privacy at the source,has been widely deployed in Smart Health Systems.However,existing ciphertext policy attribute encryption schemes face a number of challenges.For example,decryption costs are high,ciphertexts are too long and data is tampered with.To address these security issues and performance problems currently faced by privacy protection schemes for smart healthcare systems,this paper proposes a policy hidden attribute encryption scheme supporting cloud auditing and a lightweight policy is hidden attribute encryption scheme supporting searchable encryption for Smart Health Systems based on the CP-ABE scheme,with the following work:(1)A ciphertext policy attribute encryption scheme that supports partial hiding of access policies and cloud auditing(PHCA)is proposed.The LSSS linear secret sharing scheme is chosen as the access policy for this scheme.The access policy hiding of data is achieved based on the bilinear technique of ensemble order;the third-party auditing mechanism is introduced,and the data integrity is verified using data aggregation and batch verification techniques;the outsourcing decryption technique is used to reduce the decryption overhead of the Smart Health System.Finally,Finally,comparative performance analysis shows that this solution has clear advantages.(2)Based on the first scheme,the Lightweight searchable anonymous attribute encryption scheme(Ls-ABE)is proposed.In this scheme,the data user’s attribute name is anonymised by a Hash function,thus avoiding the disclosure of the user’s attribute privacy from the access policy;the CP-ABE technique is combined with the searchable encryption technique to achieve a fast search function for encrypted data keywords.In addition,the cloud performs the user search task while implementing the user identity verification function and pre-decryption function,reducing the computational burden on the user.By proving the security of the Decisional Bilinear Diffie-Hellman(DBDH)hypothesis,it is shown that the scheme satisfies indistinguishability in selected plaintext and selected keyword attacks.Theoretical analysis and experiments show that the scheme has good performance.