# Can you explain “k out of n” from the VCS paper by Naor and Shamir

I am new to visual cryptography. I’ve just read the paper “Visual Cryptography” by Moni Naor and Adi Shamir and I'm stuck on the chapter about the “$k$ out of $n$” construction. I am aware that, on page 8, there is a step-by-step explanation on how to construct it… but I still do not understand how it works.

Specifically:

• At function $h$ (number 1) – How does one get that function?
• Also, related to the notation $S^b_t$ – can someone explain what that $t$ stands for?

Any help is appreciated, but I guess it would probably be best if someone could give me a somewhat simple example that shows how to construct a “$k$ out of $n$” visual cryptography scheme.