Security system based on optical image encryption
Jong-Wook Han, Eun‐Soo Kim · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1997
We propose a new data protection method for the security system which controls the entrance of authorized persons. The basic idea is that the input image is encrypted by performing optical exclusive-OR (XOR) operations with the key bit stream that are generated by digital encryption algorithms. The gray level input image is converted to eight bit planes which are represented on a liquid crystal device (LCD). The key data represented on different LCD is reproduced to eight bit planes by lenslet arrays. The optical XOR operations between the key data and the bit planes are performed by polarization encoding method. The results of XOR operations which are detected by a CCD camera are converted to the encrypted gray level image and the image is used a an input to the joint transform correlator for comparison with reference images. We present some simulation results that verify this proposed method.