On Space and Design of Topological Graphic Passwords For Information Networks

Graphical passwords are already used in a wide range of scientific areas, especially, dynamic networks. OR code is a successful example. We estimate the spaces of topological graphic passwords (Topsnut-GPWs) that can be use conveniently and have higher level security in information networks by mean of topological structures and colorings/labellings of graph theory. We show that a type of special trees, called caterpillars, can be used to design the Topsnut-GPWs, since caterpillars admit many graph labellings and deduce lobsters having some graph labellings. And we discuss harmonious labellings and provide a new type of harmonious labellings. We point that it is easy for converting Topsnut-GPWs into text-based passwords, but not in turn in general.