Opto-digital spectrum encryption by using Baker mapping and gyrator transform

•A concept of spectrum information hidden technology is proposed in this paper.•Both the spatial and spectrum information of the hyperspectral image are protected by using the proposed encrypted scheme.•Some parameters generated during the encryption process will be regarded as the additional keys to enhancing the security of the encryption algorithms.

A concept of spectrum information hidden technology is proposed in this paper. We present an optical encryption algorithm for hiding both the spatial and spectrum information by using the Baker mapping in gyrator transform domains. The Baker mapping is introduced for scrambling the every single band of the hyperspectral image before adding the random phase functions. Subsequently, three thin cylinder lenses are controlled by PC for implementing the gyrator transform. The amplitude and phase information in the output plane can be regarded as the encrypted information and main key. Some numerical simulations are made to test the validity and capability of the proposed encryption algorithm.