Optical Encryption of a Binary Image by Phase Modulation of the Wavefront Song, Jaehun; Moon, Inkyu; Lee, Yeonho;
We present a new scheme for optical encryption of a binary image. In our method, the original binary data page is first divided into two identical pages. In each data page, the “on” and “off” pixels are represented by two discrete phases that are 90° apart. The first page corresponds to the phase conjugation of the second page, and vice versa. In addition, the wavefront of the two data pages is changed simultaneously from planar to spherical, for better encryption. The wavefront modification is represented by an extra phase shift, which is a function of position on the wavefront. In this way the two separate pages are both encrypted, and therefore the pages cannot be distinguished in a CCD. If the first page is used as an encrypted data page, then the second page is used as the decryption key, and vice versa. The decryption can be done by simply combining the two encrypted data pages. It is shown in our experiment that encryption and decryption can be fully accomplished in the optical domain.
Optical security;Encryption;Phase modulation;
J. Zheng and X. Li, “Image authentication using only partial phase information from a double-random-phase-encrypted image in the Fresnel domain,” J. Opt. Soc. Korea 19, 241-247 (2015).
I. H. Lee, “Accumulation encoding technique based on double random phase encryption for transmission of multiple images,” J. Opt. Soc. Korea 18, 401-405 (2014).
P. Refregier and B. Javidi, “Optical image encryption based on input plane and Fourier plane random encoding,” Opt. Lett. 20, 767-769 (1995).
B. Javidi, G. Zhang, and J. Li, “Encrypted optical memory using double-random phase encoding,” Appl. Opt. 36, 1054-1058 (1997).
O. Matoba and B. Javidi, “Encrypted optical memory system using three-dimensional keys in the Fresnel domain,” Opt. Lett. 24, 762-764 (1999).
J. W. Han, C. S. Park, D. H. Ryu, and E. S. Kim, “Optical image encryption based on XOR operations,” Opt. Eng. 38, 47-54 (1999).
J. A. Davis, D. E. McNamara, D. M. Cottrell, and T. Sonehara, “Two-dimensional polarization encoding with a phase-only liquid-crystal spatial light modulator,” Appl. Opt. 39, 1549-1554 (2000).
P. C. Mogensen and J. Glückstad, “A phase-based optical encryption system with polarisation encoding,” Opt. Commun. 173, 177-183 (2000).
G. Unnikrishnan, M. Pohit, and K. Singh, “A polarization encoded optical encryption system using ferroelectric spatial light modulator,” Opt. Commun. 185, 25-31 (2000).
R. L. Eriksen, P. C. Mogensen, and J. Glückstad, “Elliptical polarisation encoding in two dimensions using phase-only spatial light modulators,” Opt. Commun. 187, 325-336 (2001).
C. J. Cheng and M. L. Chen, “Polarization encoding for optical encryption using twisted nematic liquid crystal spatial light modulators,” Opt. Commun. 237, 45-52 (2004).
G. Biener, A. Niv, V. Kleiner, and E. Hasman, “Geometrical phase image encryption obtained with space-variant subwave-length gratings,” Opt. Lett. 30, 1096-1098 (2005).
G. Biener, A. Niv, V. Kleiner, and E. Hasman, “Space-variant polarization scrambling for image encryption obtained with subwavelength gratings,” Opt. Commun. 261, 5-12 (2006).
A. Alfalou and C. Brosseau, “Dual encryption scheme of images using polarized light,” Opt. Lett. 35, 2185-2187 (2010).
M. Dubreuil, A. Alfalou, and C. Brosseau, “Robustness against attacks of dual polarization encryption using the Stokes-Mueller formalism,” J. Opt. 14, 094004 (2012).