An identification patch having a plasmonic resonance structure may be used to ensure that an article is counterfeit-proof. The identification patch may be formed by a printing process, such as roll-to-roll printing or nanoimprinting, to create a distinctive ordered pattern of resonance elements. When the plasmonic resonance structure is irradiated, the ordered pattern of resonance elements produces a unique spectral response that is associated only with the counterfeit-proof article. The counterfeit-proof article may be a metal component or an integrated circuit. The resonant absorption of the plasmonic resonance structure may be measured to verify the authenticity of the article before use of the article.