Many researches about JPEG2000 chaotic encryption scheme have been proposed recently. In this paper, we adopt the encryption scheme proposed by J. Fang and modify its encryption operations by adding the action of cipher feedback. The reason why we do this modification is that it can make the same plaintext with the same key stream have different ciphertext. Beside that, we also use the CCS-PRBG as the key generator to replace the counter mode AES employed in the F&S system. The experimental results show that our proposed encryption scheme not only can provide high security but also speed performance improved.