Abstract: Deniable ring authentication protocol allows a sender to deny an authentication and his identity is anonymous to the receiver. In this work, we propose a new deniable ring authentication protocol based on the multi-receiver encryption scheme. The receiver encrypts an authentication key with multi-receiver encryption scheme and sends it to the sender. The sender decrypts it using his private key to obtain the authentication key and uses this key to authenticate messages. This protocol only requires two communication rounds and its deniability holds in the concurrent setting without requiring timing assumption due to the multi-receiver encryption.