Single-Pixel Imaging Authentication Using Sparse Hadamard Spectrum Coefficients

We experimentally present optical authentication using a small number of Hadamard spectrum coefficients in single-pixel imaging (SPI). A method is applied to generate sparse Hadamard spectrum coefficients in the SPI. By randomly selecting and using a small number of Hadamard spectrum coefficients (e.g., less than 8.0% of Nyquist limit), information of an object (i.e., plaintext) can be effectively hidden in the decrypted object. Although the decrypted object cannot visually render information about the plaintext, it can be effectively authenticated. Optical experiment is conducted to verify feasibility and effectiveness of the proposed optical authentication method. It is expected that the proposed method can provide a promising insight for single-pixel optical authentication.