Chosen-Ciphertext Attack Secure Public-Key Encryption with Keyword Search

As the use of cloud storage for various services increases, the amount of private personal information along with data stored in the cloud storage is also increasing. To remotely use the data stored on the cloud storage, the data to be stored needs to be encrypted for this reason. Since “searchable encryption” is enable to search on the encrypted data without any decryption, it is one of convenient solutions for secure data management. A public key encryption with keyword search (for short, PEKS) is one of searchable encryptions. Abdalla et al. firstly defined IND-CCA security for PEKS to enhance it’s security and proposed consistent IND-CCA secure PEKS based on the “robust” ANO-CCA secure identity-based encryption(IBE). In this paper, we propose two generic constructions of consistent IND-CCA secure PEKS combining (1) a hierarchical identity based encryption (for short, HIBE) and a signature scheme or (2) a HIBE, an encapsulation, and a message authentication code (for short, MAC) scheme. Our generic constructions identify that HIBE requires the security of a signature or a MAC as well as the weaker “ANO-CPA security (resp., IND-CPA security)” of HIBE than “ANO-CCA security (resp., IND-CCA security)” of IBE required in for achieving IND-CCA secure (resp., consistent) PEKS. Finally, we prove that our generic constructions satisfy IND-CCA security and consistency under the security models.