Abstract
We introduce a method for firing nearly invisible, two-dimensional (2D) code on ceramic product surfaces and a 2D code-reader system, equipped with a smartphone and an ultraviolet (UV) light, to extract encoded character information (public and encrypted secret information). We created the nearly invisible 2D code to add character information to ceramic surfaces without impairing the ceramics’ colors and patterns as much as possible. When irradiated by UV light, the code is visible to the naked eye, emitting a pale-blue light. The 2D code-reader system uses a smartphone camera and a 2D code-recognition algorithm to extract character information from the 2D code reflected on the smartphone’s display. However, only smartphones that have access to digital keys can decrypt the encrypted secret information. We successfully fired this 2D code on ceramic surfaces and extracted public and secret information by using iOS and Android-based 2D code-reader system.
