Dynamic Searchable Public-key Encryption

With the fast development of the cloud storage,more and more clients store the data in cloud server to save their storage space.To ensure confidentiality of their private data,all data should be encrypted before being uploaded to the honest-but-curious cloud server.Searchable encryption has been used to search on the encrypted data stored in the cloud,and it will not reveal the plaintext information of the stored ciphertexts.However,it will cause a great waste of storage space if the ciphertexts stored in the cloud server can't be deleted.So the ciphertexts need to be dynamically updated while maintaining data privacy.To the best of our knowledge,the existing dynamic searchable encryption schemes are all based on symmetric encryption.Until now,the research community has not yet proposed a dynamic searchable public-key encryption(DSPE)scheme.It is a very challenging work to propose and implement a DSPE scheme.The DSPE scheme adopts the idea of structure encryption to ensure efficient search and delete ciphertexts.We employ both logical and physical deletion to realize the deletion of ciphertexts.We first logically delete the ciphertexts and then physically delete the ciphertexts,which makes the deletion of ciphertexts more secure.The implementation of DSPE is based on bilinear map and its semantic security is proved in random oracle model based CBDH assumption.We coded DSPE scheme and evaluated its performance in keyword search and file deletion.The experiment results showed that the proposed DSPE scheme has better performance in ciphertexts operation.