A security paper or board product carrying micro or nano structures such as diffractive optical elements is formed in which the diffractive structures are integrated into the security paper or board product in the manufacturing process. A security package carrying diffractive structures is manufactured wherein diffractive structures are integrated into the security package at a manufacturing stage of the security package material. A security package contains authentication information in the form of diffractive structures. The diffractive structures are included in the security package in at least in one of the following forms: as embossed in the package material, as part of the size or paste or resin used in the manufacturing process of the security package, or as part of the ink used in printing the security package or the security package material.