NEW (k, k) VISUAL SECRET SHARING SCHEMES USING HIERARCHICAL STRCUTURE TECHNIQUE

Abstract

Visual secret sharing(VSS) schemes is a method that excodes a secret image into shadow images (called shadows) and the decoder does not need complex calculations. With the help of overhead projector(or image editing package), the shared secret can be decoded directly by the human visual system without the knowledge of cryptography and the cryptographic computations. Most recent papers about VSS scheme are dedicated to study a higher contrast or a smaller share size in VSS schemes. Smaller size means that the number of columns are smaller when the number of rows of the share matrices in VSS scheme[1] are the same. In this paper, we propose a novel hierarchical method for constructing VSS schemes with significantly less share size than other previously methods.