Cryptanalysis of a Chaotic Key based Image Encryption Scheme

TL;DR

This paper demonstrates a chosen ciphertext attack that can fully break a recent chaos-based image encryption scheme using minimal plaintext-ciphertext pairs, highlighting vulnerabilities in chaos cryptography.

Contribution

It presents the first known cryptanalysis of a specific chaos-based image encryption scheme, exposing its security flaws and demonstrating how to compromise it with limited data.

Findings

A chosen ciphertext attack can recover the system with only two plaintext-ciphertext pairs.

The encryption scheme's reliance on chaotic maps does not ensure security against cryptanalysis.

The attack reveals critical vulnerabilities in the scheme's design.

Abstract

Security of multimedia data is a major concern due to its widespread transmission over various communication channels. Hence design and study of good image encryption schemes has become a major research topic. During the last few decades, there has been a increasing in chaos-based cryptography. This paper proposes an attack on a recently proposed chaos based image encryption scheme. The cryptosystem under study proceed by first shuffling the original image to disturb the arrangement of pixels by applying a chaotic map several times. Second, a keystream is generated using Chen's chaotic system to mix it with the shuffled pixels to finally obtain the cipher image. A chosen ciphertext attack can be done to recover the system without any knowledge of the key. It simply demands two pairs of plaintext-ciphertext to completely break the cryptosystem.