Comment on “RCME: A Reputation Incentive Committee Consensus-Based for Matchmaking Encryption in IoT Healthcare”

Recently, Yang et al. proposed a reputation incentive committee consensus-based matchmaking scheme (IEEE Transactions on Services Computing, 2024), claiming to achieve indistinguishability under adaptive chosen ciphertext attacks (IND-CCA2). In this work, we present a plaintext recovery attack against their scheme under the adaptive chosen ciphertext attack model, analyze the design and proof flaws enabling the attacks, and suggest a countermeasure to achieve the IND-CCA2 security.