Keyword search protocol with privacy preservation using ID-based proxy reencryption

摘要

The data owner encrypts the data stored in the cloud to protect data privacy. However, when it comes to user revocation, the data owner must re-encrypt all data in order to prevent revoked users from decrypting the ciphertext. To reduce the computational cost of the data owner while simultaneously supporting privacy preservation, this paper proposes an efficient keyword search scheme by using identity (ID)-based proxy re-encryption technology. When a user sends a query request to the cloud server, the cloud server returns the corresponding query results encrypted by using a proxy re-encryption algorithm. Effective user revocation is achieved by simply managing re-encryption keys rather than re-encrypting the entirety of the data. Additionally, the proposed scheme supports preservation of privacy in query results. Analytical results demonstrate that the proposed protocol significantly reduces the computation and communication costs of the data owner while achieving secure user revocation.