Construction of $(4,8)$-schemes of visual cryptography on the base of a class of linear hash functions

In the work, with the use of visual cryptography, a $(4,8)$-scheme is constructed for sharing secret, which is a black and white image. To construct the $(4,8)$-scheme, the $(4,4)$-scheme of visual cryptography and a class of linear hash functions are used. It is shown that using this class makes it possible to build a secure scheme with an acceptable relative contrast of the recovered secret black and white image.