Two-Phase Image Encryption Scheme Based on FFCT and Fractals

Abstract

This paper blends the ideas from recent researches into a simple, yet efficient image encryption scheme for colored images. It is based on the finite field cosine transform (FFCT) and symmetric-key cryptography. The FFCT is used to scramble the image yielding an image with a uniform histogram. The FFCT has been chosen as it works with integers modulo p and hence avoids numerical inaccuracies inherent to other transforms. Fractals are used as a source of randomness to generate a one-time-pad keystream to be employed in enciphering step. The fractal images are scanned in zigzag manner to ensure decorrelation of adjacent pixels values in order to guarantee a strong key. The performance of the proposed algorithm is evaluated using standard statistical analysis techniques. Moreover, sensitivity analysis techniques such as resistance to differential attacks measures, mean square error, and one bit change in system key have been investigated. Furthermore, security of the proposed scheme against classical cryptographic attacks has been analyzed. The obtained results show great potential of the proposed scheme and competitiveness with other schemes in literature. Additionally, the algorithm lends itself to parallel processing adding to its computational efficiency.

ArMTFr: a new permutation-based image encryption scheme

“…They may be classified as spatial domain techniques (Zhang and Xiao, 2014) or frequency domain techniques. In the second class of techniques, both the finite field cosine transform (FFCT) (Lima et al, 2013;Mikhail et al, 2017), and the discrete fractional random transform (DFRNT) (Guo et al, 2010) have been successfully applied in image encryption. Spatial domain techniques are generally more computationally efficient compared to frequency domain techniques.…”

“…An image enciphering scheme is either a stream cipher or block cipher. In block ciphers, the plaintext is divided into blocks of a fixed size and the encryption function is applied to each block (Mikhail et al, 2017;Ahmad and Alam, 2009). Various modes of chaining the blocks can be used to achieve different tradeoffs among error propagation, security and parallel processing of the blocks.…”

“…Fractals have been used for pseudo-random numbers generation in Abd-El-Haleem et al (2013). Moreover, fractals have been used in key stream generation for image encryption in Abd-El-Hafiz et al (2014) and Mikhail et al (2017). Furthermore, fractals have been employed by researchers in data hiding (El-Khamy et al, 2008).…”

“…Evaluating the quality of the results of applying an encryption scheme is very important as it reflects the weaknesses and the good aspects in the cryptosystem employed. When dealing with image encryption, one should be aware that specialised tests are needed to judge the quality of the encrypted image and this fact arises from the nature of images that are more challenging compared to text data (Abd-El-Hafiz et al, 2014;Mikhail et al, 2017). There are qualitative measures for evaluating the quality of an encrypted image.…”

A Novel Hybrid Secure Image Encryption Based on Julia Set of Fractals and 3D Lorenz Chaotic Map

“…The fractals generate infinitely complex patterns and show repetition and self-similarity at different scales. It is the repeating process of images and is familiar patterns since the whole universe consists of fractals in different forms [30][31][32][33][34][35][36][37][38][39][40][41][42][43]. In this context, we have designed a cryptosystem based on shuffling with Julia set of fractals key and chaos theory.…”