Grayscale object authentication based on ghost imaging using binary signals

In recent years, either quantum or classical ghost imaging has attracted much attention in many fields. Here, we report grayscale object authentication based on ghost imaging using binary signals. It is found that binary signals can be applied at reference and object beam arms, which provides a promising alternative to explore the potential of ghost imaging for some applications. Reducing the data size with only two quantization levels is beneficial to the storage and transmission. One numerical example, i.e. , grayscale object authentication, is given to illustrate the feasibility of the proposed method, and it is highly expected that more studies can further explore the ghost imaging system using binary signals for other applications.