In this paper, a fast image encryption and authentication scheme is presented. In the proposed scheme, a 512-bit message authentication code generated by a keyed hash function is embedded into the image by reversible data embedding technique. Then the embedded image is masked by the pseudo random sequence in feedback mode. The embedded message authentication code not only plays the role of authentication but also contributes to the image encryption. The algorithm can effectively resist against chosen-plaintext attack or known-plaintext attack. Theoretical analysis and computer simulation indicate that our algorithm is efficient and highly secure.