In a first aspect, a multilayer film includes a holographic image layer, a first heat-shrinkable layer and a first adhesive layer between the holographic image layer and the first heat-shrinkable layer. In a second aspect, an authentication label includes a holographic image layer, a first heat-shrinkable layer, a first adhesive layer between the holographic image layer and the first heat-shrinkable layer, and a back adhesive layer.

A system for controlling access to secured resources using a security token having a hologram embossed thereon is provided. A key is split into a user key and a complimentary key based on a mask, wherein key values in the user key correspond to idle state values in the complimentary key and vice versa. The user key is used to generate a user key array, that is used to generate a three-dimensional virtual image that is holographically embossed onto a security token. The hologram is merged with a corresponding hologram for the complimentary key and the combination compared to an image of an ensemble of the key. The combination can be mergers of images or extractions of holograms. If a match is found, within a tolerance, an access grant signal is sent to the secure resources, thereby securing the resources based on presence of the security token.

The invention relates to a security element with manipulation detection, in particular a security label or a transferable element, having the following layers: a) a first layer which is an embossed support substrate or a support substrate (1) with a coating layer (6) that has an optically active structure (7) or a first liquid crystal layer, b) a second layer which is a liquid crystal layer (3), c) a light-absorbing layer (4), and d) an adhesive layer (5), wherein the adhesion between the layers a. and b. is lower than the adhesion between the layers b., c., and d., and the security element has a color shift effect.

A system includes a plurality of optical identifiers and a reader for the optical identifiers. Each optical identifier has an optical substrate and a volume hologram (e.g., with unique data, such as a code page) in the optical substrate. The reader for the optical identifiers includes an illumination source (e.g., a laser), and a camera. The illumination source is configured to direct light into a selected one of the optical identifiers that has been placed into the reader to produce an image of the associated volume holograms at the camera. The camera is configured to capture the image. The captured image may be stored in a digital format by the system.

A security device is provided, including a first transparent layer having an optically variable effect generating relief structure formed in a surface thereof; a reflection enhancing layer extending over the relief structure and following the contour of the relief; and a second transparent layer extending over the reflection enhancing layer, the lateral extent of the second transparent layer being less than the whole area of the security device and corresponding to the lateral extent of the reflection enhancing layer. The first and/or second transparent layer includes one or more optically effective substances such that the appearance of the optically variable effect generated by the relief structure is different when viewed through the first transparent layer compared with when viewed through the second transparent layer, at least under illumination at a wavelength at which at least one of the optically effective substance(s) is visible.

A display member according to this invention includes a plurality of pixels. At least one of the plurality of pixels includes a relief structure formation layer including a first region configured to display a predetermined color on a condition, and a second region different from the first region, a first layer made of a first material, and covering at least the first region, and a second layer made of a second material different from the first material, and covering the first layer. The display member displays an image based on a distribution of the first region on the condition that the display member is observed in the oblique direction, and displays an image based on a distribution of the second region on a condition that the display member is observed with transmitted light.

The invention relates to a method for authenticating a diffractive element, e.g., a hologram, on an object or document (2), wherein at least two images of the diffractive element are recorded by means of a portable device (1). The recordings are taken in different spatial orientations of the portable device in relation to the diffractive element. Recording data are created from the images and the associated spatial orientations. The recording data are electronically compared with reference data. The comparison can be performed locally or in a server-based manner.

Cryptographic techniques for encrypting images, and decrypting and reconstructing images, are provided to facilitate preventing unauthorized access to images. A holographic cryptographic component (HCC) can generate a global image comprising a scaled version of a source image and random content, generate a phase hologram representing the global image, and encrypt the phase hologram to generate an encrypted hologram based on a random phase mask, which can be the private encryption key. To reconstruct the source image, an HCC can overlay a phase mask, which can be a conjugate of the random phase mask, on the encrypted hologram to decrypt it, and can illuminate the decrypted hologram with a coherent light source. The source image is only reconstructed properly if the correct phase mask is used. If HCC applies the encryption process repetitively to the same source image, HCC can generate a different encrypted hologram in each run.

The invention relates to a multilayer body with a volume hologram layer and a partial opaque layer, arranged on a surface of the volume hologram layer, which is present in a first area and is not present in a second area. The invention furthermore relates to a method for the production of such a multilayer body, as well as a security element and security document with such a multilayer body.

There is provided an optical structure having a quantization phase difference structure on one surface of a quantization phase difference structure layer, wherein in the quantization phase difference structure, a plurality of quantization projecting portions in a constant size and a plurality of quantization recessed portions in a constant size are aligned, wherein a multiple diffraction region has the quantization phase difference structure where ribbed projecting portions, in which the quantization projecting portions are aligned in one direction, are arranged adjacent to and alternately with groove-like recessed portions, in which the quantization recessed portions are aligned parallel to the ribbed projecting portions, and wherein the multiple diffraction region is a quantization phase difference structure configured to reproduce a plurality of reproduction points discrete in one direction and arranged regularly.