Constructing designated server public key encryption with keyword search schemes withstanding keyword guessing attacks

Abstract

Designated server public key encryption with keyword search (dPEKS) removes the secure channel requirement in public key encryption with keyword search (PEKS). With the dPEKS mechanism, a user is able to delegate the search tasks on the ciphertexts sent to him/her to a designated storage server without leaking the corresponding plaintexts. However, the current dPEKS framework inherently suffers from the security vulnerability caused by the keyword guessing (KG) attack. How to build the dPEKS schemes withstanding the KG attacks is still an unsolved problem up to now. In this work, we introduce an enhanced dPEKS (edPEKS) framework to remedy the security vulnerability in the current dPEKS framework. The edPEKS framework provides resistance to the KG attack by either the outside attacker or the malicious designated server. We provide a semi-generic edPEKS construction that exploits the existing dPEKS schemes. Our security proofs demonstrate that the derived edPEKS scheme achieves the keyword ciphertext indistinguishability, the keyword ciphertext unforgeability, and the keyword trapdoor indistinguishability if the underlying dPEKS scheme satisfies the keyword ciphertext indistinguishability and the hash Diffie-Hellman problem is intractable. In addition, a concrete edPEKS scheme is presented to show the instantiation of the proposed semi-generic construction.KEYWORDS designated server, keyword guessing attack, malicious designated server, outside attacker, public key encryption with keyword search

A Decryptable Attribute-Based Keyword Search Scheme on eHealth Cloud in Internet of Things Platforms

“…However, [28] still needs a secure channel in trapdoor transmission process. Recently, the PEKS schemes proposed in [29]- [31] also adopted similar idea by including a data sender's private key in the generation of keyword ciphertexts to solve the problem of inside keyword guessing attacks. Lattice-based schemes proposed in [32] and [33] employed preimage sampleable function to generate the authenticated keyword ciphertexts for resisting inside KGAs.…”

Provable secure lightweight attribute‐based keyword search for cloud‐based Internet of Things networks

“…In a SE scheme, by generating some trapdoors associated with some keywords, users can ask the server to retrieve their desired data files such that the server is prevented from learning any partial information about the keywords and contents of the outsourced data files. The existing SE schemes can be categorized into public‐key SE (PKSE) schemes 9–12 and symmetric SE (SSE) schemes 13–16 . Although SSE schemes are significantly more efficient than PKSE schemes, they suffer from the critical and expensive key distribution 17 problem.…”