In this paper, we implement a novel optical information processing tool termed as gyrator wavelet transform for the application of double image encryption using amplitude- and phase-truncation approach. This approach enhances the key space in an asymmetric cryptosystem by adding supplementary security layers, i.e., family of mother wavelet and the gyrator transform order. Double input images bonded with random phase masks are independently gyrator transformed. Amplitude truncation of obtained spectrum generates individual and universal keys while phase truncation generates two real-valued functions. Each of the retrieved amplitude function is discrete wavelet transformed, which results into four different frequency bands. We have fused the obtained wavelet spectrum of an individual image by again gyrator transforming them following amplitude- and phase truncation. The obtained real-valued functions corresponding to each image are bonded to form the encrypted image. After using the correct universal key, individual asymmetric key, type of wavelet, and correct gyrator transform order, the original images are retrieved successfully. Numerical simulation results prove that the proposed scheme is more flexible and effective than existing wavelet fusion schemes.

Date Published: 15 June 2015
PDF: 6 pages
Proc. SPIE 9654, International Conference on Optics and Photonics 2015, 96542D (15 June 2015); doi: 10.1117/12.2181708

Published in SPIE Proceedings Vol. 9654:
International Conference on Optics and Photonics 2015
Kallol Bhattacharya, Editor(s)