Research On The Encryption Algorithm Of Double-image Based On The Fractional Fourier Transformation And Pixel Scrambling

Image encryption is an important method for the protection of secret informationin network transmission and storage process. Due to parallelism and rapidity of theoptical information processing system, it has been a new focus on the research ofimage encryption by using optical methods. Traditional optical encryption scheme isbased on the double random phase encoding technology (DRPE) with the Fouriertransform. At present Fractional Fourier transform (FRFT) has aroused the researchinterests of optical researchers. Among them, double random phase encodingtechnique has attracted more attention at home and abroad for its high security.Aiming at disadvantages of the traditional image encryption algorithm, such ascrosstalk effect between the images, system complicated and low iterative calculationefficiency, a new encryption algorithm is presented. This algorithm combines therandom phase encoding in the fractional Fourier domain with the pixel scramblingtechnology to realize multi-image encryption. The experimental results describe thatcombining optical image encryption technology with digital image scramblingtechnology can improve the safety and reliability of the encryption system. The maincontents are as follows:Firstly, aiming at disadvantages of traditional image encryption algorithm thismethod propose that pixel scrambling is done on the original images before encoding,which depends on the pixel scrambling operation in the decryption procession. Thesafety of this decryption system relies on the sensory commend and the random ofphase masker and fractional Fourier order.Secondly, a new image encryption algorithm is studied and destruct a imageencryption system which uses two kinds of pixel scrambling operation、 twicefractional Fourier transformations and two random phase maskers to encrypt original images for a smooth white noise image.Finally, the image encryption system is achieved. The simulation results showthe feasibility of this method, the security analysis reflects this method has multiplekeys and a large key space.