A method for verifying the authenticity of a security document by means of a camera-equipped cellphone comprises steps of acquiring a transmission mode image and a reflection mode image of the security document. Transmitted light through a plurality of perforations in a substrate of the security document is evaluated by means of the cellphone. Then, a relative positioning of the perforations with respect to a printed security features is determined, and the security document is considered “authentic” if the determined positions and the acquired images substantially correspond to pre-stored “templates” for the security document. The perforations are structured such that they are not visible to the naked eye of a human observer which makes it harder to counterfeit the security document.