The encryption method to share a secret binary image and its decryption system

ABSTRACT

In this paper, an encryption method to share a secret binary image was proposed. This divides the image to be encrypted into an arbitrary number of images and encrypts them using XOR process with different binary random images which was prepared by the means of the XOR process, too. Each encrypted slice image can be distributed to the authenticated ones. However, we transfer the encrypted images to the binary phase masks to strengthen the security power, that means phase masks can not be copied with general light-intensity sensitive tools such as CCDs and cameras. For decryption, we used the Mach-Zehnder interferometer in which linearly polarized two light beams in orthogonal direction, respectively. The experimental result proved the efficiency of the proposed method.

REFERENCES

• 1: P. Refregier and B. Javidi, "Optical image encryption based on input plane and Fourier plane random encoding," Optics Letters, Vol. 20, No. 7, pp. 767--769, 1995.
• 2: J. W. Han, C. S, Park, D. H. Ryu, and E. S. Kim, "Optical image encryption based on XOR operations," Optical Engineering, vol. 38, no. 1, pp. 47--54, 1999.
• 3: J. W. Han, S. H. Lee, and E. S. Kim, "Optical key bit stream generator," Optical Engineering, Vol. 38, No. 1, pp. 33--38, 1999.
• 4: G. Unnikrishnan, J. Joseph, and K. Singh, "Optical encryption system that uses phase conjugation in a photorefractive crystal," Applied Optics, vol. 37, pp. 8181--8185, 1998.
• 5: O. Matoba and B. Javidi, "Encrypted optical memory system using three-dimensional keys in the Fresnel domain," Optical Letters, vol. 24, pp. 762--764, 1999.
• 6: O. Matoba and B. Javidi, "Encrypted optical storage with wavelength-key and random phase codes," Applied Optics, vol. 38, pp. 6785--6790, 1999.
• 7: O. Matoba and B. Javidi, "Encrypted optical storage with angular multiplexing," Applied Optics, vol. 38, pp. 7288--7293, 1999.
• 8: L. G. Neto and Y. Sheng, "Optical implementation of image encryption using random phase encoding," Optical Engineering, vol. 35, pp. 2459--2463, 1996
• 9: T. Nomura, "Phase encoded joint transform correlators as an optical encryption decoder." San Diego SPIE Meeting, pp. 246--252, 1998.
• 10: J.-Y. Kim, S.-J. Park, C.-S. Kim, J.-G. Bae, and S.-J. Kim, "Optical image encryption using interferometry-based phase masks," Electronics Letters, vol. 36, no. 10, pp. 874--875, 2000.
• 11: Dong-Hoan Seo, Jong-Yun Kim, et al., "Visual Cryptography based on optical interference encryption technique," proceedings of SPIE, vol. 4386, pp. 172--180, 2001
• 12: <u>http://plc.cwru.edu/tutorial/enhanced/files/1c/light/light.htm</u>
• 13: Hecht, Optics, 2nd Ed, Addison-Wesley, Ch. 9, 1987.

INDEX TERMS

Keywords:
cryptography, data security, image reconstruction, optical imaging