Generic Construction of Forward Secure Public Key Authenticated Encryption with Keyword Search

In this paper, we propose a generic construction of forward secure public key authenticated encryption with keyword search (FS-PAEKS) from PAEKS. In addition to PAEKS, we employ 0/1 encodings proposed by Lin et al. (ACNS 2005). Here, forward security means that a newly generated ciphertext is not allowed to be searched by previously generated trapdoors. We also show that the Jiang et al. FS-PAEKS scheme (The Computer Journal 2023) does not provide forward security. Our generic construction is quite simple, and it can also be applied to construct forward secure public key encryption with keyword search (FS-PEKS). Our generic construction yields a comparably efficient FS-PEKS scheme compared to the previous scheme. Moreover, it eliminates the hierarchical structure (Abdalla et al. (JoC 2008)) or attribute-based feature (Zeng et al. (IEEE Transactions on Cloud Computing 2022)) of the previous generic constructions which is meaningful from a feasibility perspective.