Privacy-Preserving and Forward Public Key Encryption With Field-Free Multi-Keyword Search for Cloud Encrypted Data
Yang Lu, Jiguo Li
Abstract
With the excessive growth of data and the rapid development of cloud technology, cloud adoption is expanding rapidly nowadays. To achieve the purpose of privacy protection, the cloud data may be transmitted, stored and retrieved in enciphered form. Public key searchable encryption (PKSE) provides a feasible solution for efficient retrieval over enciphered data without decryption. However, traditional PKSE suffers from some problems, such as keyword guessing (KG) attack and unauthorized ciphertext retrieval. In this paper, we present a practical PKSE scheme named forward public key authenticated encryption with field-free conjunctive keyword search (FW-PAE-FCKS). The scheme enjoys several good properties (e.g., flexible multi-keyword search with no keyword fields, forward ciphertext retrieval) and can effectively withstand the KG attack and the unauthorized ciphertext retrieval. Moreover, the executive overhead of the scheme is very friendly to the user terminals with limited resources as it totally avoids the operations with high computation cost (such as hash-to-point, bilinear pairing) on the user side. Based on the infeasibility assumption of the hash Diffie-Hellman problem, we formally prove its security without using the random oracle. Comparison analysis and experimental results show that it outperforms the existing related schemes.