Image encryption using fractional integral transforms: Vulnerabilities, threats, and future scope

Abstract

With the enormous usage of digital media in almost every sphere from education to entertainment, the security of sensitive information has been a concern. As images are the most frequently used means to convey information, the issue related to the privacy preservation needs to be addressed in each of the application domains. There are various security methods proposed by researchers from time to time. This paper presents a review of various image encryption schemes based on fractional integral transform. As the fractional integral transforms have evolved through their applications from optical signal processing to digital signal and digital image processing over the decades. In this article, we have adopted an architecture and corresponding domain-based taxonomy to classify various existing schemes in the literature. The schemes are classified according to the implementation platform, that may be an optical setup comprising of the spatial modulators, lenses, and charge-coupled devices or it can be a mathematical modeling of such transforms. Various schemes are classified according to the methodology adopted in each of them and a comparative analysis is also presented in tabular form. Based on the observations, the work is converged into a summary of various challenges and some constructive guidelines are provided for consideration in future works. Such a narrative review of encryption algorithm based on various architectural schematics in fractional integral transforms has not been presented before at one place.

High-security image encryption by multiplexing phase encoding in domains of dual optical transforms

“…The sensitivity of the encryption scheme should be evaluated from two aspects. First, in the encryption phase, input keys with small differences should produce completely different ciphertext images; second, in the decryption phase, small changes to the correct decryption key will not effectively recover the original image (Kaur, Agarwal, et al 2022). Therefore, in this section, the encryption process and the decryption process are examined from both sides.…”

“…The communication channels over which the image information is transferred are responsible for the addition of some noise in the form of degradation or distortion (Kaur, Agarwal, et al 2022). To corrupt the useful information, the attacker may introduce noise into the encrypted image so that the user cannot successfully recover the original image after decryption (Kaur and Kumar 2018).…”

A novel conservative chaos driven dynamic DNA coding for image encryption

“…The optical image encryption systems utilize optical setups (lenses, spatial lens modulators, etc.) [2][3][4], double random phase encoding (DRPE) with optically or electronically generated random phase masks [4][5][6][7][8], and mathematical modeling with integral transforms [4,9,10]. Such systems have the advantage of sending complex data in parallel and are also capable of carrying out usually time-consuming operations in a faster way, therefore are found suitable in image encryption.…”

“…Such systems have the advantage of sending complex data in parallel and are also capable of carrying out usually time-consuming operations in a faster way, therefore are found suitable in image encryption. Besides having above mentioned clear advantages, the optical processes governed by the integral transforms possess the linearity and symmetry properties which make the optical encryption system vulnerable to various cryptanalytic attacks [4,[11][12][13]. On the other hand, DNA computing, since its advent in 1994 [14], has attracted the attention of researchers due to some of its peculiar features like huge informationcarrying capacity, parallelism, ultra-low energy consumption etc.…”

“…In such hybrid methods, the chaotic dynamical systems have been mainly utilized to introduce the non-linear effects in the substitution and permutation of pixels in a variety of ways. On the other hand, the optical transforms, DNA operations have been utilized to do encoding/decoding of image pixels that too sometimes under the control of chaotic systems [4]. As the present manuscript deals with hybrid chaos and DNA based image encryption, therefore we are elaborating more on this category in our further discussion.…”