Dynamic optical stealth hydrogel for information encryption.

Abstract

Physical-layer optical encryption offers intuitive readout and resistance to unauthorized copying. Here, we report a dynamically reconfigurable platform based on a polyacrylamide hydrogel lenticular lens array, where effective line-density matching acts as a physical key. The array decodes otherwise invisible information from printed media and smartphone screens, enabling reversible information display and concealment for optical encryption and anti-counterfeiting.