Abstract: The present invention relates to a security item comprising a security certificate comprising data that has been encrypted using a private encryption key. The data is operable to be decrypted using a public decryption key associated with the private encryption key in order to authenticate the security certificate. The present invention also relates to systems and methods for authenticating the security certificate.

Abstract: A bleeding or fugitive printing ink is disclosed and claimed which can be printed by the method of dry or wet offset or letterpress. This ink allows, when printed on security documents and dried, to prevent attempts of forgery or counterfeit in that the ink contains at least one dyestuff which is sensitive to organic solvents and other chemical reagents. The ink, when printed, forms a solid, polymerized or cross-linked binder matrix on the surface of the document when the printings are submitted to energy radiation, or by an oxypolymerization reaction. This matrix is formed near immediately, in the case of oxypolymerization within 24 hours, in contrast to conventional bleeding printing inks whose matrixes do not really dry and remain liquid in the interstices of the substrate.