Image encryption method for decryption area limitation using directed area and poker mapping

Abstract

The invention provides an image encryption method for decryption area limitation using a directed area and poker mapping. The method is characterized in that firstly, a stable point of the minimum epiboly is obtained through the minimum epiboly of a decryption position, a random triangle is generated through the stable point, an MD5 value and an SHA-1 value of an image to be encrypted, and a userkey, and intermediate encryption parameters are generated through the direction area of the triangle; an initial value and parameter values of chaotic mapping are generated through the intermediate encryption parameters, and the chaotic mapping is driven to generate a random image with the same size as the image to be encrypted; and poker mapping scrambling and overall xor encryption are carried out on randomly selected lines and rows of the image to be encrypted through the chaotic mapping and the random image, so that an encrypted image is generated. Compared with the conventional method, the method provided by the invention has the advantages that the decryption area is limited, so that the encrypted image can only be decrypted within a specific range; and plain text attributes and therandom image are introduced, so that encryption steps for the different encrypted images are different, and the safety is further improved.

Description

technical field [0001] The invention belongs to the intersecting field of image security and image signal processing, relates to an image encryption method, in particular to an image encryption method for defining a decryption area mapped to a directed area and playing cards. Background technique [0002] Digital image encryption, in essence, is to convert meaningful plaintext images into random noise-like random images under the joint action of encryption functions and encryption keys, the purpose of which is to make the real information to be transmitted unable to be intuitively perceived. [0003] Traditional image encryption algorithms usually use encryption strategies based on pixel confusion or pixel position replacement, for example: Peng Zaiping, 2014. (Peng Zaiping, Wang Chunhua, Lin Yuan, etc. A new type of four-dimensional multi-wing hyperchaotic attractor and its application in image encryption [J]. Acta Physica Sinica, 2014,63(24):240506-240506.) XOR encryption ...

AI Technical Summary

Problems solved by technology

[0010] Guo Yi, 2015, Yang Lu, 2014, Shao Liping, 2015 and Shao Liping, 2016 Compared with the traditional image encryption algorithm, by introducing the plaintext features of the image to be encrypted, the strategy’s ability to resist chosen / known plaintext attacks is improved, but Same as traditional image encryption methods: Peng Zaiping, 2014, Zhang X, 2014, Liu X, 2016, Parvin Z, 2016, Liu Y, 2016, ZhangX, 2017, Jain A, 2016, Pareek N K, 2013, Zhang X, 2016, Hua Like Z, 2015, Zhu H, 2016, Xu L, 2016, Tang Z, 2016, the security of the key is considered without considering the limitation of the decryption position, so that the encrypted image can be decrypted at any position, instead of only It can only be decrypted in a specific location, so there is a big security risk

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