Optical Image Encryption Based On Scrambling Technique And Fractional Fourier Transofrm

With the development and popularization of the global network ofinformation technology, the information technology has been rapid deepeningdependence. Information security has become a new issue that can not be ignoredin front of us! Image encryption technology is an important part of informationsecurity. The previous image encryption technology, we achieved by computer,DSP and other traditional methods has been unable to meet the currentprocessing a large amount of information and data requirements. Optical imageencryption technology is a new information security technology; it is animportant supplement to the traditional image encryption technology. Opticalimage encryption technology itself has a faster processing speed, paralleltransmission, low production cost. And the wavelength of light, storagecapacity, at the same time it has amplitude, phase, wavelength, polarizationand other key attributes, these advantages make the application of opticalimage encryption is more effective.Based on the study of optical image encryption theory and optical devices,through to the domestic and foreign typical optical encryption structure modeland the simulation experiment system of in-depth interpretation and analysis,a combination of several current popular image scrambling technology; forsingle use one or several kinds of image scrambling technology, as well asthe specific problem of image encryption using a simple computer systemexistence, carry out theoretical research and experimental model design. Theconcrete contents include:1、 we propose a “Logistic” chaos mapping image used in puzzlestransformation and cats face two kinds of scrambling transformation combinedencryption model. This model is a one-dimensional“Logistic” map chaoticsequences generated, used in the above two kinds of encryption modelscrambling in. Then the gray scrambling and scrambling position method basedon image encryption. Through the experimental analysis, sensitivity analysis,encryption adjacent element correlation results are keys that anti cutting,anti noise analysis and so on, that the algorithm has a good encryption,decryption effect.2、proposed a new encryption model optical fractional Fourier transformand image scrambling technology based on. This model is based on fractional Fourier transform, and scrambling technology as the image preprocessingalgorithm application puzzle transformation and cats face, in order to improvethe security robustness and invisibility, through the iterative process, andeventually realize the original image optical encryption. Through theexperiment of this model has the flexibility, good robustness test certificate,can resist shear, rotation, noise and other attacks, and through the gray levelhistogram, the computer simulation of the mean square error map andautocorrelation analysis chart analysis, more clear that the model has goodsecurity, confidentiality.