Searchable Encryption Scheme Based on CPABE with Attribute Update in a Cloud Medical Environment

With the development in cloud storage, hospitals outsource the encrypted electronic medical records to the cloud services for economic saving. A cloud medical environment where the attribute is frequently updated, the existing searchable encryption schemes cannot support both ciphertext search and fine-grained access control. Therefore, combining ciphertext policy attribute-based encryption with searchable encryption technology, a cryptographic retrieval scheme supporting attribute update is proposed. Attributes can be updated frequently and partial decryption is transferred to the cloud storage server. Security analysis shows that the scheme can protect security and privacy under the DBDH assumption and the experimental results with real data show that the scheme is an efficient and practical application.