Novel hyperchaos-based scrambling and plaintext pixel dynamic correlation image encryption method

Abstract

The invention discloses a novel hyperchaos-based scrambling and plaintext pixel dynamic correlation image encryption method, which belongs to the technical field of image encryption and comprises the following steps of an image encryption algorithm, key generation, a pixel dynamic correlation scrambling process, a diffusion process, a decryption process and a simulation result and attack test. The method has the beneficial effects that a nonlinear cross-coupled hyperchaotic mapping is designed, the mapping has the characteristics of wider hyperchaotic interval, no periodic window, more complex dynamic behavior and better randomness of the generated state sequence class, and only one chaotic state sequence of which the number is the same as that of plaintext pixels is used, so that the complexity of the method is greatly reduced. Dynamic position transformation of the chaotic state sequence related to plaintext pixels is realized, the capabilities of resisting known plaintext attacks and selecting plaintext attacks are enhanced, the chaotic sequence which is the same as a scrambling stage is used, the utilization rate of chaotic state mapping is improved, the algorithm only needs one round of scrambling and diffusion operation, and the calculation complexity of the algorithm is reduced.

Description

technical field [0001] The invention belongs to the technical field of image encryption, and in particular relates to a new image encryption method based on super-chaos scrambling and plaintext pixel dynamic correlation. Background technique [0002] At present, many encryption algorithms based on chaos have been proved by cryptanalysts to be insecure and easy to be cracked when attacked [36,117-123]. The most important thing is that the key stream used in the process of scrambling and diffusion completely depends on the key, that is to say, although these algorithms have a certain relationship with the plaintext when forming the key, but As long as the key does not change, the key stream generated by the key will not change during the scrambling and diffusion stages, so when the same key is used to encrypt different plaintext images, the key stream is not safe, because The attacker can choose to bypass the direct attack key, but obtain the keystream through known-plaintext...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is that the dynamic behavior of the chaotic system adopted in the current image encryption algorithm based on chaos is not complicated enough, the chaotic interval is narrow, and there is even a period window, thereby causing the key space to be small; The chaotic state sequence is used as the key stream in the scrambling and diffusion phase, which only depends on the key, so the key stream cannot resist known plaintext attack and chosen plaintext attack; in the scrambling and diffusion phase, different chaotic state sequences are usually used , so that the utilization rate is not high, and the computational complexity and storage space of the algorithm are increased to improve the defects, so a new image encryption method based on hyper-chaos scrambling and plaintext pixel dynamic correlation is proposed

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