Generating visually coherent encrypted images with reversible data hiding in wavelet domain by fusing chaos and...

Area of Science:

• Cryptography
• Digital Image Processing
• Information Security

Background:

• Traditional image encryption transforms images into noise-like patterns, indicating the presence of ciphers.
• This approach can alert adversaries to potential encrypted data.

Purpose of the Study:

• To propose a novel image encryption algorithm.
• To generate visually coherent and meaningful cipher images.
• To reduce storage and transmission costs for encrypted images.

Main Methods:

• A permutation-substitution subroutine using Arnold-3D map and a delayed logistic map.
• Hiding a partial cipher within a reference image using integer wavelet transform.
• Embedding cipher pixels into sub-bands via 4-to-1 pixel encoding with a Cantor-like pairing function.

Main Results:

• The algorithm produces visually coherent cipher images.
• Lossless encryption and perfect reconstruction of the reference image are achieved.
• The use of simple pairing functions prevents cipher size increase, reducing costs.

Conclusions:

• The proposed algorithm offers a secure and efficient method for digital image transmission.
• It maintains visual coherence in cipher images, unlike conventional techniques.
• The approach effectively reduces storage and transmission overheads.