Breaking an Image Encryption Algorithm Based on DNA Encoding and Spatiotemporal Chaos.

Area of Science:

• Cryptography
• Information Security
• Applied Mathematics

Background:

• A novel image encryption algorithm, IEA-DESC, utilizing DNA encoding and spatiotemporal chaos was recently proposed.
• The algorithm employs pixel diffusion, DNA encoding, DNA-base permutation, and DNA decoding for generating cipher-images.

Purpose of the Study:

• To critically analyze the security vulnerabilities of the IEA-DESC algorithm.
• To demonstrate the ineffectiveness of certain components and the overall security weaknesses.

Main Methods:

• Cryptanalysis of the IEA-DESC algorithm's components, including pixel diffusion and DNA operations.
• Equivalence simplification of the algorithm to a core set of operations.
• Application of chosen-plaintext and chosen-ciphertext attacks to recover the secret key.

Main Results:

• Pixel diffusion in IEA-DESC is cryptanalytically ineffective.
• The combination of DNA encoding and decoding is equivalent to a bitwise complement operation.
• The DNA-base permutation is a fixed shuffling operation, rendering it insecure.
• IEA-DESC can be simplified to a form dependent solely on its equivalent secret key.

Conclusions:

• IEA-DESC possesses inherent security defects that compromise its overall security.
• The equivalent secret key of IEA-DESC is vulnerable to recovery via chosen-plaintext and chosen-ciphertext attacks.
• The proposed attack methods are theoretically sound and experimentally validated as effective and efficient.