Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Feb 22;25(3):400.
doi: 10.3390/e25030400.

Cryptanalyzing and Improving an Image Encryption Algorithm Based on Chaotic Dual Scrambling of Pixel Position and Bit

Affiliations

Cryptanalyzing and Improving an Image Encryption Algorithm Based on Chaotic Dual Scrambling of Pixel Position and Bit

Shuqin Zhu et al. Entropy (Basel). .

Abstract

An image encryption algorithm for the double scrambling of the pixel position and bit was cryptanalyzed. In the original image encryption algorithm, the positions of pixels were shuffled totally with the chaotic sequence. Then, the 0 and 1-bit positions of image pixels were scrambled through the use of another chaotic sequence generated by the input key. The authors claimed that the algorithm was able to resist the chosen-plaintext attack. However, through the analysis of the encryption algorithm, it was found that the equivalent key of the whole encryption algorithm was the scrambling sequence T in the global scrambling stage, the pixel bit level scrambling sequence WT and the diffusion sequence S. The generation of scrambling sequence T is related to the sum of all pixel values of the plaintext image, while the generation of WT and S is not associated with the image to be encrypted. By using a chosen-plaintext attack, these equivalent key streams can be cracked so as to realize the decoding of the original chaotic encryption algorithm. Both theoretical analysis and experimental results verify the feasibility of the chosen-plaintext attack strategy. Finally, an improved algorithm was proposed to overcome the defect, which can resist the chosen-plaintext attack and has the encryption effect of a "one time pad".

Keywords: chaotic system; chosen plaintext attack; cryptanalysis; image encryption.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Iterative results of the chaotic map (1).
Figure 2
Figure 2
Simulation results of chosen plaintext attack. (a) The 256 × 256 ciphertext to be decoded; (b) The 384 × 512 ciphertext to be decoded; (c) The corresponding decoding result of (a); (d) The corresponding decoding result of (b).
Figure 3
Figure 3
The flow chart of the improved encryption process.
Figure 4
Figure 4
The encryption and decryption effect. (a) The 256 × 256 encrypted image. (b) The decrypt image of (a). (c) The 384 × 512 encrypted image. (d) The decrypted image of (c).
Figure 5
Figure 5
The decrypted images by using the error keys. (a) Decryption result of “cameraman”. (b) Decryption result of “peppers”.

References

    1. Lin Y.-T., Wang C.-M., Chen W.-S., Lin F.-P., Lin W. A Novel Data Hiding Algorithm for High Dynamic Range Images. IEEE Trans. Multimed. 2016;18:196–211. doi: 10.1109/TMM.2016.2605499. - DOI
    1. Diaconu A.-V. Circular inter–intra pixels bit-level permutation and chaos-based image encryption. Inf. Sci. 2016;355–356:314–327. doi: 10.1016/j.ins.2015.10.027. - DOI
    1. Dragoi I.-C., Coltuc D. On Local Prediction Based Reversible Watermarking. IEEE Trans. Image Process. 2015;24:1244–1246. doi: 10.1109/TIP.2015.2395724. - DOI - PubMed
    1. Li C., Lin D., Lu J., Hao F. Cryptanalyzing an Image Encryption Algorithm Based on Autoblocking and Electrocardiography. IEEE MultiMed. 2018;25:46–56. doi: 10.1109/MMUL.2018.2873472. - DOI
    1. Zhu S., Deng X., Zhang W., Zhu C. Secure image encryption scheme based on a new robust chaotic map and strong S-box. Math. Comput. Simul. 2023;207:322–346. doi: 10.1016/j.matcom.2022.12.025. - DOI

LinkOut - more resources