Identity-based Public Key Keyword Searchable Encryption Scheme with Denial Authentication

The development of cloud storage technology achieves resource sharing, which reduces users data management overhead. Searchable encryption technology protects users privacy and supports ciphertext retrieval, making it easy for users to find encrypted data in the cloud. Although existing public key searchable encryption schemes support authentication, the denial property is not implemented. To protect better the senders identity privacy, an Identity-based Public Key keyword Searchable Encryption scheme with Denial Authentication (IDAPKSE) is proposed. In the proposed scheme, the sender uploads the ciphertext and has the ability to deny that he or she uploaded the ciphertext to the cloud server. At the same time, the receiver can confirm the origin of the ciphertext, however, even with the cooperation of a third party, the receiver can not prove the facts in his/her possession to the third party. Under the random oracle model, based on the Bilinear Diffie-Hellman(BDH) and Decisional Bilinear Diffie-Hellman(DBDH) assumptions, the proposed scheme satisfies unforgeability of the ciphertexts, and indistinguishability of ciphertexts and trapdoors.