Cryptanalyzing an Image-Scrambling Encryption Algorithm of Pixel Bits

TL;DR

This paper critically evaluates the security of an image-scrambling encryption algorithm, revealing vulnerabilities through ciphertext-only and plaintext attacks, and demonstrating the effectiveness of multimedia processing techniques in cryptanalysis.

Contribution

It provides a comprehensive cryptanalysis of a typical image-scrambling encryption algorithm, highlighting its vulnerabilities and proposing effective attack strategies.

Findings

Remaining correlation in ciphertext reveals plaintext information

Position-scrambling scope enables efficient known-plaintext attack

Multimedia processing techniques facilitate cryptanalysis

Abstract

Position scrambling (permutation) is widely used in multimedia encryption schemes and some international encryption standards, such as the Data Encryption Standard and the Advanced Encryption Standard. In this article, the authors re-evaluate the security of a typical image-scrambling encryption algorithm (ISEA). Using the internal correlation remaining in the cipher image, they disclose important visual information of the corresponding plain image in a ciphertext-only attack scenario. Furthermore, they found that the real scrambling domain--the position-scrambling scope of ISEA's scrambled elements--can be used to support an efficient known or chosen-plaintext attack on it. Detailed experimental results have verified these points and demonstrate that some advanced multimedia processing techniques can facilitate the cryptanalysis of multimedia encryption algorithms.