Visual Cryptography Implementation within Dynamic Group for Secure Data Access

摘要

Visual Cryptography is one of the cryptography techniques which are used in secret sharing scheme where a secret image was encoded into transparencies and stacking of any out of transparencies reveals the secret image. By stacking fewer transparencies is unable to extract any information about the secret. We also discussed the deletions and additions of users in a dynamic user group. In order reduce the overhead of generating and distributing transparencies in user changes it, in this paper we proposed a VC scheme with unlimited based on the prospect mold. The proposed scheme allows changing dynamically in order to include new transparencies without regenerating and redistributing the original transparencies. In specifically, an extended VS scheme based on a prospect mold and basic matrices is proposed. An equation is derived from the fundamental definitions of the VC scheme here, and then in VC scheme achieving maximal contrast can be designed by using the derived equations. And the maximum contrasts with two are implicitly solved in this paper.