Image encryption using discrete orthogonal Stockwell transform with fractional Fourier transform

In this article, a new image encryption algorithm has been proposed for image security. This algorithm is created with discrete orthogonal Stockwell transform (DOST) and fractional Fourier transform (FrFT). It has been used for image encryption and decryption. The DOST has improved computational efficiency and delivered a spatial time-frequency depiction similar to the other transform like discrete wavelet transform (DWT). In this method, encryption of the image has been used DOST with independent specific keys and its fractional-order and analyzed the effect of DOST. Thereafter, decrypted the image through the inverse process of the image encryption. The encrypted image has been achieved using the correct order and keys. We used different images and plotted their encrypted histogram and scatter, respectively. Then, calculate the correlation coefficient of the original, encryption image, encryption time, and entropy. Moreover, evaluate the variation between encrypted and original images using the number of pixel change rates (NPCR) and unified average changing intensity (UACI). Also, it compared the results of the proposed algorithm with the existing algorithm.