Cryptanalyzing an Image-Scrambling Encryption Algorithm of Pixel Bits
This work exposes vulnerabilities in a widely used multimedia encryption method, which is incremental as it builds on existing cryptanalysis techniques.
The authors analyzed the security of an image-scrambling encryption algorithm (ISEA), revealing that internal correlations in cipher images allow visual information disclosure in ciphertext-only attacks, and the scrambling domain enables efficient known or chosen-plaintext attacks, with experimental verification.
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.