Chaotic encryption and digital watermark image verification method and system

Abstract

The invention discloses an image verification method and system based on chaotic encryption and digital watermarking, and the method comprises a chaotic encryption step: selecting a to-be-encrypted image, and carrying out the chaotic encryption to obtain a first encrypted image; a watermark encryption step: embedding the first watermark code text into the first encrypted image to form a second encrypted image containing the first watermark code text; a verification step: judging whether the watermark information of the second encrypted image can be extracted according to the pre-extracted watermark processing result: if the watermark codes can be decrypted and the watermark codes are consistent when the similarity of the watermark codes is detected, continuing to execute the decryption step; otherwise, finishing the subsequent processing of the second encrypted image; and a decryption step: performing watermark removal processing to restore the first encrypted image, and decrypting the first encrypted image to obtain a decrypted image. According to the method, the defects of a chaotic encryption algorithm in resisting selected plaintext attacks are overcome by adopting the digital watermarking, so that the method has good shearing resistance and robustness, and image information transmission is safer.

Description

technical field [0001] The invention relates to the technical field of information security, in particular to an image verification method and system for chaotic encryption and digital watermarking. Background technique [0002] With the advancement of technology, people have changed from traditional text communication to the current use of image information to communicate on the Internet. Once encrypted images are intercepted and destroyed during transmission, or replaced with pictures with viruses, the recipient It is not easy to detect and will cause damage to the recipient's property and other aspects; [0003] In the early 1990s, researchers discovered the natural connection between chaos and cryptography. Because the chaotic system well reflects the characteristics of randomness, it can well match the design criteria of a perfect cryptographic system. The encryption system based on chaotic dynamics has strong flexibility in design and can provide a good balance betwee...

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Problems solved by technology

[0002] With the advancement of technology, people have changed from traditional text communication to the current use of image information to communicate on the Internet. Once encrypted images are intercepted and destroyed during transmission, or replaced with pictures with viruses, the recipient It is not easy to detect and will cause damage to the recipient's property and other aspects;

[0003] In the early 1990s, researchers discovered the natural connection between chaos and cryptography. Because the chaotic system well reflects the characteristics of randomness, it can well match the design criteria of a perfect cryptographic system. The encryption system based on chaotic dynamics has strong flexibility in design and can provide a good balance between security and computing efficiency. It is especially suitable for encrypting digital images with a large amount of data and realizing the security of digital images. Real-time, secure transmission; initially in 1998, American scholar Jessica Fridrich proposed the first general-purpose image encryption architecture, which implements a security through two core processes of "permutation" and "substitution". image encryption system; therefore, it has been extensively studied by scholars in the field of image encryption in recent years, but encryption technology still faces many difficulties, and traditional chaotic image encryption algorithms are difficult to resist known plaintext attacks;

[0004] In order to solve the encryption algorithm's ability to resist known plaintext attacks, researchers at home and abroad have proposed improved image encryption algorithms on this basis. The classic methods include using hyper-chaos or composite chaotic systems to complete color image encryption, such as the above American scholar Jessica Fridrich proposed the first general-purpose image encryption architecture: in the scrambling phase, the pixel value of each point is attacked sequentially under the action of the key stream, and at the same time, the influence of each pixel is spread to the entire ciphertext image , so as to ensure that the encryption system can effectively resist chosen-plaintext attacks, but this method has a high time complexity and requires a long processing time;

[0005] Due to the disadvantages of the chaotic encryption algorithm itself, that is, it is difficult to resist the chosen plaintext attack, even if the chaotic encryption algorithm is improved, it is only slightly improved on the basis of it, and it is difficult to resist new or specific chosen plaintext attacks. Only defend against the more common selected plaintext, such as resisting differential attacks;

[0006] Chaos degradation occurs when implemented in a platform with a certain range of precision, because its output states cannot be uniformly distributed, and since there is no complex behavior, their trajectories can be easily predicted using certain techniques, and they There are only two cases of chaotic range, narrow or discontinuous. If the chaotic map has a narrow or discontinuous chaotic range, when its parameters are subject to some external interference, its chaotic properties are likely to be destroyed.

[0007] When verifying the security of chaotic encryption algorithms, researchers pay too much attention to statistical data and resisting a single chosen plaintext attack instead of in-depth analysis of the ability of the algorithm to resist specific attacks, and it is difficult to guarantee whether it has good shear resistance and robustness. Rod

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