Visual cryptography based on optical interference encryption technique
Dong-Hoan Seo, Jong‐Yun Kim, Sang‐Su Lee, Se-Joon Park, Woong H. Cho, Soo-Joong Kim · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
In this paper, we proposed a new visual cryptography scheme based on optical interference that can improve the contrast and signal to noise ratio of reconstructed images when compared to conventional visual cryptography methods. The binary image being encrypted is divided into any number of n slides. For encryption, randomly independent keys are generated along with another random key based on a XOR process of random keys. The XOR process between each divided image and each random key produces the encryption of n encrypted images. These encrypted images are then used to make encrypted binary phase masks. For decryption, the phase masks are placed on the paths of a Mach-Zehnder interferometer.