A spatiotemporal chaotic image encryption scheme based on self adaptive model and dynamic keystream fetching technique

摘要

This paper proposes a block chaotic image encryption algorithm based on self-adaptive and dynamic key stream fetching technique (DKSFT) which makes use of a non-adjacent spatiotemporal chaotic system coupled with Tent-Sine system (NASC-TSS) for the chaotic orbit generation. The chaotic dynamics of NASC-TSS has incredible cryptographic properties contrasted with the existing 1D chaotic map. Firstly, a bit-level permutation strategy based on circular-shift operation is suggested which focuses to lessen the implications propelled by the classical permutationarchitectures. Finally, in the block based diffusion phase, a control parameter is designed to update the initial condition of the employed chaotic system. Subsequently, a unique keystream is generated for various plain-image processing which in turn elevates the complexity of breaking the proposed algorithm under known attacks. Furthermore, the pixel handling in both the permutation and the diffusion stages are done with DKSFT in which the keystream selection corresponds to the pixel position of the permutated-image. The adopted strategies such as self adaptive model and DKSFT can keep up the characteristics of the keystream fluctuating and dodge different sorts of attacks, undoubtedly the known-plaintext and chosen plaintext attacks. The investigation outcomes against a series of rigorous security analysis shows that the strong execution of the proposed cryptosystem against various attacks. These highlight an appealing security level with just a single round of encryption operation, making the algorithm impeccably appropriate for some unique interactive media applications.