Proxy re-encryption conjunctive keyword search against keyword guessing attack

Public key encryption with keyword search enables users to retrieve keywords from encrypted data, which can protect data confidentiality without losing the search operability. However, it is also vulnerable to keyword guessing attacks. In this paper, we propose a conjunctive keywords searchable encryption with designated tester (dPECK) to prevent the keyword guessing attacks. It can support multiple-keywords query at one time, i.e. conjunctive keywords search. We formulate the security notions for the conjunctive keyword search with the designated tester and present an efficient scheme which is proven secure in the standard model. Moreover, we extend the dPECK to proxy re-encryption dPECK (Re-dPECK) in order to enable the search proxy function. At last, the comparison and efficiency simulation demonstrates that this scheme has the lower computation and storage overhead.