A novel visual cryptography scheme based on Steiner trades

The existence of a secure channel for sharing secret key, is the main problem in the symmetric cryptography. This problem is solved by the asymmetric cryptography (Public key cryptography). Computation has the main rule in the public key cryptography. Here, we investigate the visual cryptography schemes. Human vision decodes the secret image in the visual cryptography scheme and no computations required for this aim. The visual cryptography scheme has an unconditional security. In this system, the secret image is shared between n participants and k participants can recover the secret image by stacking image layers. Various constructive models of the visual cryptography schemes have been constructed up to now. We investigate one type of the visual cryptography scheme that is based on BIBDs (Balanced Incomplete Block Design). In this paper, we introduce and construct new visual cryptography schemes based on homogeneous Steiner trades. The concept of homogeneous Steiner trades is closely related to BIBDs.