A Reversible Secret Sharing Scheme Based on GF(2^8)

Lin and Chan proposed reversible secret sharing scheme in 2010. The advantages of this scheme are as follows: a low distortion, high capacity of shadow images and usage of the reversible method. However, this scheme has some problems. First, the number of participants is limited because of modulus prime number m. Second, the overflow can occur by additional operations in the embedding procedure. Finally, the coefficient of (t-1)-th degree polynomial can be zero due to the property of the cover image pixel. The proposed scheme solves these problems of the Lin and Chan´s scheme. In order to solve these problems, a new polynomial technique are utilized in the proposed scheme. In the experimental results, PSNR of their scheme is decreased with the increase of embedding capacity. However, in the proposed scheme, even if the embedding capacity increase, PSNR value of about 45dB or more is maintained uniformly.