Design and Analysis of a Novel Digital Image Encryption Scheme

TL;DR

This paper introduces a fast, secure image encryption scheme combining substitution and permutation with feedback mechanisms, making it resistant to common cryptanalytic attacks and suitable for secure digital image transmission.

Contribution

The paper presents a novel image encryption method that integrates multi-round substitution, key feedback, and dynamic pixel scrambling, enhancing security and efficiency over existing schemes.

Findings

High security against linear and differential cryptanalysis

Efficient encryption with fast processing speed

Robustness due to multi-round substitution and permutation

Abstract

In this paper, a new image encryption scheme using a secret key of 144-bits is proposed. In the substitution process of the scheme, image is divided into blocks and subsequently into color components. Each color component is modified by performing bitwise operation which depends on secret key as well as a few most significant bits of its previous and next color component. Three rounds are taken to complete substitution process. To make cipher more robust, a feedback mechanism is also applied by modifying used secret key after encrypting each block. Further, resultant image is partitioned into several key based dynamic sub-images. Each sub-image passes through the scrambling process where pixels of sub-image are reshuffled within itself by using a generated magic square matrix. Five rounds are taken for scrambling process. The propose scheme is simple, fast and sensitive to the secret key. Due to high order of substitution and permutation, common attacks like linear and differential cryptanalysis are infeasible. The experimental results show that the proposed encryption technique is efficient and has high security features.