Security documents often incorporate security devices to prevent or hinder counterfeiters. Disclosed herein are security devices that include a fluid or fluids within the devices. Such devices, and security documents that include them, afford new techniques to check whether a security document is a legitimate or counterfeit copy.

Security documents often incorporate security devices to prevent or hinder counterfeiters. Disclosed herein are security devices that include a fluid or fluids within the devices. Such devices, and security documents that include them, afford new techniques to check whether a security document is a legitimate or counterfeit copy.

An anti-counterfeiting pattern having an optically variable structure, comprising lithographic lines and gravure blind embossed relief lines printed on a carrier. The lithographic lines are a set of lithographic curve lines having a curvature, the widths of the lithographic curve lines changing from thick to thin, or thin to thick. The gravure blind embossed relief lines are a set of curve lines corresponding to the lithographic lines, and having the same curvature. The relief lines are overprinted on the lithographic lines with a width variation identical to that of said lithographic lines. Accurate overprinting of the two printing types forms a curved relief structure wherein the width of the lines changes continuously. When a printed product is rotated and observed, a continuously variable optical effect will be seen, which is visual, readily to identify, anti-copying and difficult to forgery.

A method for determining whether a candidate barcode is genuine involves acquiring an image of an original barcode; determining, from the image of the original barcode, a deviation of a continuous edge of the original barcode from a nominal shape; encoding the deviation as signature data for the original barcode; storing the signature data for the original barcode on a storage device; acquiring an image of the candidate barcode; determining, from the image of the candidate barcode, a deviation of a continuous edge of the candidate barcode from the nominal shape; retrieving the signature data for the original barcode from the storage device; comparing the signature data for the original barcode with the signature data for the candidate barcode; and making a determination that the candidate barcode is genuine or not genuine based on a result of the comparison.

A method for determining whether a candidate barcode is genuine involves acquiring an image of an original barcode; determining, from the image of the original barcode, a deviation of a continuous edge of the original barcode from a nominal shape; encoding the deviation as signature data for the original barcode; storing the signature data for the original barcode on a storage device; acquiring an image of the candidate barcode; determining, from the image of the candidate barcode, a deviation of a continuous edge of the candidate barcode from the nominal shape; retrieving the signature data for the original barcode from the storage device; comparing the signature data for the original barcode with the signature data for the candidate barcode; and making a determination that the candidate barcode is genuine or not genuine based on a result of the comparison.

A method for producing a multilayer body, as well as a multilayer body produced thereby. A single- or multi-layered first decorative ply is applied to a carrier ply with a first and a second side. A metal layer is applied to the side of the first decorative ply facing away from the carrier ply and structured such that the metal layer is provided with a first layer thickness in one or more first zones and is provided with a second layer thickness different from the first layer thickness in one or more second zones, wherein in particular the second layer thickness is equal to zero. A single- or multi-layered second decorative ply is applied to the side of the metal layer facing away from the first decorative ply and structured using the metal layer as mask such that the first or second decorative ply is at least partially removed in the first or second zones.

A method for producing a multilayer body, as well as a multilayer body produced thereby. A single- or multi-layered first decorative ply is applied to a carrier ply with a first and a second side. A metal layer is applied to the side of the first decorative ply facing away from the carrier ply and structured such that the metal layer is provided with a first layer thickness in one or more first zones and is provided with a second layer thickness different from the first layer thickness in one or more second zones, wherein in particular the second layer thickness is equal to zero. A single- or multi-layered second decorative ply is applied to the side of the metal layer facing away from the first decorative ply and structured using the metal layer as mask such that the first or second decorative ply is at least partially removed in the first or second zones.

A security device and method of making thereof. The security device includes a colour shifting element that exhibits different colours dependent on the angle of incidence of light impinging upon the colour shifting element, and; an at least partially transparent light control layer covering at least a part of the colour shifting element and including a surface relief adapted to modify the angle of light incident upon the light control layer, wherein; the light control layer includes at least first and second functional regions having different refractive indices such that light incident upon the first functional region impinges upon the colour shifting element at a first angle of incidence, and light incident upon the second functional region impinges upon the colour shifting element at a second, different, angle of incidence.

An identification device of the present invention determines authenticity of an article with an anti-counterfeiting medium varying in a pattern of observed light depending on changes in light characteristics of radiated light, using the anti-counterfeiting medium. The identification device includes a similarity calculation unit that determines the degrees of similarity between a plurality of captured image data of the anti-counterfeiting medium obtained with differences in the light characteristics of the radiated light and reference image data corresponding to the light characteristics; and an authenticity determination unit that determines whether the degrees of similarity determined for the individual light characteristics exceed thresholds set corresponding to the individual light characteristics to make an authenticity determination on whether the anti-counterfeiting medium is genuine.

An identification device of the present invention determines authenticity of an article with an anti-counterfeiting medium varying in a pattern of observed light depending on changes in light characteristics of radiated light, using the anti-counterfeiting medium. The identification device includes a similarity calculation unit that determines the degrees of similarity between a plurality of captured image data of the anti-counterfeiting medium obtained with differences in the light characteristics of the radiated light and reference image data corresponding to the light characteristics; and an authenticity determination unit that determines whether the degrees of similarity determined for the individual light characteristics exceed thresholds set corresponding to the individual light characteristics to make an authenticity determination on whether the anti-counterfeiting medium is genuine.