Gene

Algorithm

Pixel

Image compression

Materials science

Computer security

Robustness (evolution)

Encryption

Image processing

Operating system

Biochemistry

Computer science

Sparse approximation

Politics

Image (mathematics)

Political science

Plaintext

Artificial intelligence

Composite material

Representation (politics)

Compression (physics)

Chemistry

Programming language

Compressed sensing

Bitwise operation

Ciphertext

Computer vision

Optics and Lasers in Engineering

To enhance the confidentiality and the robustness of double image encryption algorithms, a novel double-image compression-encryption algorithm is proposed by combining co-sparse representation with random pixel exchanging. Firstly, two scrambled plaintext images are expressed by the co-sparse analysis model with different row-scrambled basis matrices while the co-sparse representations could be regarded as the intermediate ciphertext. Subsequently, the co-sparse representations are compressed and encrypted concurrently by compressive sensing. Furthermore, the corresponding measurements obtained are processed by the random pixel exchanging operator and the Arnold transform. Finally, the corresponding results are combined into an enlarged image and then the resulting image is re-encrypted by the discrete fractional angular transform to improve the security of the whole algorithm. A series of numerical simulations are carried out to show the security performance of the proposed double-image compression and encryption algorithm.

Double-image compression and encryption algorithm based on co-sparse representation and random pixel exchanging