Breaking a chaotic image encryption algorithm based on modulo addition and XOR operation

TL;DR

This paper demonstrates that the MCKBA/HCKBA chaotic image encryption algorithms can be efficiently broken using only two known plain-images and cipher-images, revealing significant security vulnerabilities.

Contribution

It introduces improved cryptanalysis methods that reduce the required known plain-images from four to two, based on analyzing the properties of modulo addition and XOR operations.

Findings

MCKBA/HCKBA can be broken with two known plain-images.

The attack exploits properties of modulo addition and OR operations.

The security of the algorithms is significantly weaker than previously thought.

Abstract

This paper re-evaluates the security of a chaotic image encryption algorithm called MCKBA/HCKBA and finds that it can be broken efficiently with two known plain-images and the corresponding cipher-images. In addition, it is reported that a previously proposed breaking on MCKBA/HCKBA can be further improved by reducing the number of chosen plain-images from four to two. The two attacks are both based on the properties of solving a composite function involving the carry bit, which is composed of the modulo addition and the bitwise OR operations. Both rigorous theoretical analysis and detailed experimental results are provided.