A lossless secret image sharing scheme using a larger finite field

Recent research has made an effort to take 8b-bit value as a polynomial coefficient and use a random number as the maximum coefficient term in a Shamir’s polynomial, where b > 0. These can help improve computationl efficiency by reducing the sum of calculating polynomials, and avoid the case of the coefficient of xk− 1 being zero. However, such research still has the issues of requiring much extra storage space, lossy secret image, shadow images with large size, and storing permutation key. To solve the above issues, in this paper, we propose a novel scheme which takes 8b-bit value as a polynomial coefficient, designs a bit-level method and runs under Galois Field GF(28b). Experimental results show that this scheme improves existing similar schemes on several aspects, such as less extra storage space and higher computational performance.