A new image encryption method based on rotation transformation and chaos theory was proposed, which used chaos function to generate random phase mask (chaotic random phase mask). In the proposed technique, the image was encrypted using gyrator transform and two chaotic random phase masks. In the proposed method, the image was encrypted by using rotation transform and two chaotic random phase masks, and the chaotic random phase mask was generated by using three chaotic functions: Logistic map, Tent map and Kaplan⁃Yorke map. The computer simulations were presented to verify the validity of the proposed technique. By calculating the mean square deviation, the robustness of the blind decryption algorithm based on the seed value of rotation angle and chaotic random phase was evaluated, and the optical implementation scheme of encryption and decryption technology was given.