Improved chaos‐RSA‐based hybrid cryptosystem for image encryption and authentication

Abstract

This article puts forward a fast chaos-RSA-based hybrid cryptosystem to secure and authenticate secret images. The SHA-512 is used to generate a 512-bit initial key.The RSA system is used to encrypt the initial secret key and signature generation for both the sender and image authentication. In fact, a powerful block-cipher algorithm is developed to encrypt and decrypt images with a high level of security. At this stage, a strong PRNG based on four chaotic systems is propounded to generate high-quality keys. Therefore, an improved architecture is suggested. It performs confusion and diffusion of images with low computational complexity. In the final step, the encrypted secret key, signature, and encrypted image are combined together in order to obtain an encrypted signed image. The block-cipher algorithm is evaluated in-depth for several ordinary and medical images with different types, content, and size. The obtained simulation results demonstrate that the system enables high-level security. The entropy has achieved a value of 7.9998 which is the most important feature of randomness. A comparative study against numerous recent encryption algorithms demonstrates that the proposed algorithm provides good results.

Steganography Approach to Image Authentication Using Pulse Coupled Neural Network

“…Its primary function is to verify data integrity, i.e., that the data has not been modified in any way. Digital signatures [12,13,14] and Keyed-Hash Message Authentication Code [15,16] are most commonly used to authenticate images.…”

A novel 3D chaos-based encryption system for satellite communication

“…While traditional pseudo-random sequences are generated by multi-level shift registers or other delay elements through linear feedback [10] , chaotic sequences can be generated with only one model and initial conditions, which is very convenient and can effectively reduce the hardware resource consumption. Chaotic cryptography is used in several applications, such as medical, radar [11] , spread spectrum communication [12] , secure communication [13] , ultra-wideband communication [14] , multimedia information encryption [15][16][17][18] , etc., and is usually combined with traditional encryption methods, such as Arnold map, RSA algorithm [19] , AES algorithm [20] , to increase the overall cryptosystem complexity and security of the whole encryption system. The literature [21] uses chaotic sequences combined with fractal structures, cellular automata and linear feedback shift registers for medical images to perform multiple diffusion operations, and the complex encryption system is implemented in hardware.…”