A Novel Image Encryption Algorithm Based on Secure Hash Function and Galois Field

A novel image encryption algorithm based on secure hash function and Galois filed is proposed in this paper. We design a keystream generator based on SHA-512 for creating a matrix validated for the randomness by NIST tests. This matrix is used as a key matrix of the proposed encryption and decryption algorithms. Applying the multiplication operations between plain-image and key matrix on Galois field GF(2
⁸
) to conceal pixels information. Two scrambling matrices are generated by ascending the rows and columns of the key matrix, respectively, to change the positions of pixels. Experimental simulations and security analysis demonstrate that the proposed algorithm has high security and sensitivity to resist brute-force attacks, statistical attack, differential attack, etc.