The Research On Image Secret Sharing

As a research hotspot in applied cryptography realm, secret sharing has changed the mode of traditional encryption, decryption, digital signature and authentication, which can prevent authoritative cheating and enhance the system security. Consequently, it has important significance in saving and transmitting confidential information.The dissertation introduces that secret sharing's generation, development and applications in image's field and analysizes some proposed image secret sharing schemes. To solve these problems existed in those, compressible image shaing and multi-secret images sharing based on matrix multiplication have been designed in the dissertation, of which the contributions are as follows:1. The compressible image sharing scheme is proposed. Sufficiently considering image's two-dimensional characteristic, this scheme based on matrix multiplication theory processes image in image block. The size of the shadow image produced by the scheme is 1/t as large as that of secret image, which effectively compress the size. In comprasion with other similar ones, this scheme has many merits, such as high compression's rate, low complex degree and dispensing with pretreatment et al.2. The multi-secret images sharing scheme is proposed. Regarding image block as its basic processing unit, this scheme takes advantange of two-variable one-way function to realize a more efficient images' multi-secret sharing. Moreover, instead of generating shadow images it only announces some information owned by altogether participants, which avoids the problemes concerned with shadow images. Compared to any other multi-secret sharing schemes based on shamir's theory, it is more appropriate in image's multi-secret sharing.3. Disscussing some important arithmetics involved in schemes: including the construction of full rank matrices in finite field, matrix inversion in finite field, the design of two-variable one-way function, the selection of matrices A_i{1=i=n) and so on.At last, using VC++ 6.0 and matlab, the experiments are carried out in Window XP. The results of experiments show that these schemes are feasible.