Abstract:To effectively improve the quality of multi-image encryption and its security for data transmission, this study proposes a multi-authority multi-image encryption algorithm based on a hyperchaotic system. Specifically, bilayer cross-coupling based on the piece-wise linear chaotic map (PWLCM) is applied to L plaintext images respectively. The results are merged by exclusive-OR (XOR) to obtain a noise-like image. Then, the least significant bit embedding algorithm is used to embed the noise-like image into the (L+1)th plaintext image to obtain a semi-encrypted image. Finally, a one-dimensional cubic map is combined with a one-dimensional tent map to generate a two-dimensional cubic-tent modular map (2D-CTMM). A ciphertext image is obtained by two-step scrambling of the semi-encrypted image after it is diffused with the 2D-CTMM. The experimental results show that the proposed method, highly sensitive to plaintext and key with a large key space, can effectively resist statistical attacks and differential attacks. Moreover, the proposed algorithm enables multi-authority decryption and partial decryption by different authorized users.