Comments on “Blockchain-Assisted Public-Key Encryption With Keyword Search Against Keyword Guessing Attacks for Cloud Storage”
Keita Emura · IEEE Transactions on Cloud Computing · 2025
As a variant of PEKS (Public key Encryption with Keyword Search), Zhang it al. (IEEE Transactions on Cloud Computing 2021) introduced a secure and efficient PEKS scheme called SEPSE, where servers issue a servers-derived keyword to a sender or a receiver. In this paper, we show that information of keyword is revealed from trapdoor when an adversary is allowed to issue servers-derived keyword queries twice.