Image Encryption Algorithm Based on Matrix Semi-Tensor Product in DWT Domain

This paper proposed an image encryption method based on matrix semi-tensor product (STP) and discrete wavelet transform (DWT). Firstly, a two-dimensional chaotic system is utilized to produce random sequences. Secondly, the plaintext image is converted to wavelet coefficients based on discrete wavelet transform. Next, the wavelet coefficients are encrypted based on STP and chaotic sequences. Then the encrypted information in DWT domain are converted into space domain via inverse discrete wavelet transform (IDWT). At last, the image is diffused to obtain the encrypted image. The proposed method is highly secure against statistical attacks according to the security analysis, as the information entropy reaches 7.9971.