Security analysis of Pan et al.’s “Public-key authenticated encryption with keyword search achieving both multi-ciphertext and multi-trapdoor indistinguishability”

Abstract Recently, Pan et al. proposed the “Public-Key Authenticated Encryption with Keyword Search Achieving both Multi-Ciphertext and Multi-Trapdoor Indistinguishability” in Pan and Li (2021). However, after carefully revisiting the scheme, we found an attack on Pan et al.’s scheme. As a result, the multi-ciphertext indistinguishability of their scheme is totally broken. In addition, we also pointed out a serious mistake in the security proof of multi-trapdoor indistinguishability in Pan’s scheme.