(2,n) Visual Cryptography Scheme Based on Constant Weight Code

Based on constant weight code constructed from steiner system,a (2,n) visual cryptography scheme is proposed through research on the relation between constant weight code and (2,n) visual cryptography scheme. The design method is proposed in process of the scheme’s existence proof. The scheme can balance performance between pixel expansion and contrast much better as contrast to existing schemes. Experimental results demonstrate that pixel expansion decreases greatly and contrast is closing to maximum in the scheme.