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The public key encryption with keyword search (PEKS) scheme is a cryptographic primitive that allows a cloud server to search for a ciphertext without knowing the corresponding keyword used in the search. An expressive PEKS scheme is a variant of the PEKS scheme that supports conjunctive and disjunctive searches (expressive search). Utilising the expressive properties of an attribute-based encryption (ABE) scheme, most of the expressive PEKS schemes can be constructed from an ABE scheme. In this paper, we first give a brief review of the transformed expressive PEKS scheme by Shen et al. in 2019. Then, we present a keyword guessing attack on Shen et al.’s transformed expressive PEKS scheme and show that an adversary can correctly guess the supposedly hidden keyword.