This paper presents a new blind watermarking system based on the Discrete Cosine Transform (DCT). The system’s security is increased by encrypting the watermark image using the fractional-order Lorenz system. After converting the cover image to the YCbCr color domain, DCT is applied on the Y channel and embedding of the encrypted watermark is performed in the frequency domain. The fractional-order Lorenz system has more parameters than the integer order system, which increase the length of the system key and make it secure against brute-force attacks. Although blind detection of the watermark is not easy, the proposed algorithm successfully detects the hidden watermark by using statistical properties of the DCT coefficients. Standard imperceptibility and robustness measures are used to evaluate the proposed system, and the results are good. © 2022 IEEE.
PRNG Using Primitive Roots of Primes and its Utilization in Chess-based Image Encryption
Recently, number theory has proved its importance in cryptography because of its well-known hard problems. For instance, a primitive root for a prime number shows a special property of uniqueness when raised to different powers mod the prime number. In this paper, a Pseudorandom Number Generator (PRNG) is designed based on this property using a prime number and some of its primitive roots. The PRNG is, first, validated for utilization in cryptography applications using histograms, correlation coefficients, and the National Institute of Standards and Technology (NIST) statistical test suite. Then, the PRNG is utilized in an image encryption system and the system security is tested using statistical measures, differential attack measures, and sensitivity to one-bit change. The results are promising and in the expected good ranges. © 2022 IEEE.
Image encryption in the fractional-order domain
This paper presents a new image encryption scheme based on the fractional-order Lorenz system which gives more degrees of freedom in key generation. In the modified fractional-order system, the key length is doubled using the three fractional-orde r parameters beside the three initial conditions, which makes it invulnerable to brute-force attacks. In addition, using a very simple algorithm, based on pixel confusion only, strongly encrypted images are produced. Such an algorithm can be used in real time applications. To evaluate the algorithm and analyze the encryption results, a standard image is used. A comparison of the colored correlation coefficients (horizontal, vertical, diagonal) for different cases with respect to a fractional-order parameter and another system parameter are introduced. Moreover, the encrypted image shows high sensitivity to the fractional-order key, which appears from the wrong decryption with 0.1% change of the fractional-order parameter. © 2012 IEEE.
Design of pseudo random keystream generator using fractals
This paper presents a novel method for designing a pseudo random keystream generator (PRKG) based on fractal images. Although a fractal image has high correlation between its pixels, the proposed technique succeeds in almost eliminating this correlation and the output stream passes the NIST statistical test suite. The post-processing on the fractals is based only on a confusion process and uses a nonlinear network with a delay block to randomize the output stream. Many statistical measures and the NIST suite have been used to evaluate the processed fractals and the results are promising. As an example to validate the PRKG, the output stream is used in a simple image encryption system. The encrypted image is tested by calculating pixel correlations, differential attack measures, entropy and it also passes the NIST test suite. © 2013 IEEE.
Novel Fast Prediction Algorithm for Advanced and High Efficiency Video Coding
This paper introduces an efficient prediction algorithm tailored for advanced and high efficiency video coding, encompassing both H.264 and H.265. The proposed approach aims at replacing the standard intra prediction methodology by employing a streamlined prediction mode, which significantly reduces computational overhead and system complexity while eliminating the requirement for mode decision. By leveraging block comparison criteria, the designed method combines neighboring blocks in a linear fashion to accurately represent the target block. Extensive comparisons are conducted with the H.264 intra prediction using various video sequences and multiple evaluation criteria. The results demonstrate substantial time savings of up to 60% compared to the H.264 standard intra prediction algorithm, with a minor peak signal-to-noise ratio drop. The proposed algorithm holds promise for enhancing real-time video processing and compression in video coding systems, offering notable efficiency gains without sacrificing predictive accuracy. © 2024 IEEE.
Permutation techniques based on discrete chaos and their utilization in image encryption
To achieve the Shannon’s confusion and diffusion properties, an image encryption algorithm should include permutations and substitutions
An image encryption system based on generalized discrete maps
This paper presents a new image encryption scheme based on the fractional-order Lorenz system which gives more degrees of freedom in key generation
Image encryption algorithms using non-chaotic substitutions and permutations
This paper presents substitution and/or permutation symmetric-key encryption algorithms based on non-chaotic generators
Utilizing LFSR and Feistel networks in image encryption
This paper presents a novel method for designing a pseudo random keystream generator (PRKG) based on fractal images
A generalized framework for elliptic curves based PRNG and its utilization in image encryption
In the last decade, Elliptic Curves (ECs) have shown their efficacy as a safe fundamental component in encryption systems, mainly when used in Pseudorandom Number Generator (PRNG) design. This paper proposes a framework for designing EC-based PRNG and maps recent PRNG design techniques into the framework, classifying them as iterative and non-iterative. Furthermore, a PRNG is designed based on the framework and verified using the National Institute of Standards and Technology (NIST) statistical test suite. The PRNG is then utilized in an image encryption system where statistical measures, differential attack measures, the NIST statistical test suite, and system key sensitivity analysis are used to demonstrate the system’s security. The results are good and promising as compared with other related work. © 2022, The Author(s).