| 摘要 |
Disclosed are security articles and methods and systems for authenticating security articles using a plurality of stimuli. According to one embodiment, an illustrative security feature includes an encoded feature wherein differential activation of phosphorescent or fluorescent materials creates a machine readable code through the simultaneous presence of a source of electromagnetic radiation and a specific gas environment. A detector detects a differential spectral emission across the security feature that results from the change in gas environment. The spectral emission may be compared to an expected emissive signature to determine authenticity of the security article. |
