The invention provides a novel image
encryption method based on correlation between chaos and
plaintext. The method comprises the steps: carrying out row and column updating of a
plaintext image A, and obtaining a processed image E; employing the modular operation of a
gray level 256, changing the pixel sum of the image through the modular operation between rows and the modular operation between columns, and breaking the strong correlation between the adjacent rows and the adjacent columns of an original
plaintext image; enabling the pixel sum s of the image E to serve as the feature of the image, extracting the feature of the image, participating the generation of a key
stream, carrying out the second layer
encryption through scrambling
encryption, and obtaining an image Q; and solving a problem that a conventional
algorithm employs the same key
stream while encrypting different images. Through the gray value
diffusion of the image, the method builds the
mutual influence between two adjacent pixels, and a secret key directly participates in the output of a
ciphertext image. In order to achieve an
avalanche effect, the
mutual influence between two adjacent pixels is built through the key
stream. Meanwhile, a second group of secret keys are designed to participate in the output of the
ciphertext image, thereby achieving the third layer encryption.