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.

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.

There are provided volume holograms and combinations of lenticular lenses and holograms in particular for security applications. In embodiments, a volume hologram comprises a holographic medium (102) including a first optical interference structure which, upon illumination, replays a first image (110); wherein the first image includes a lenticular lens layer (111) including an array of lenticules and a lenticular image layer (113) including first (114) and second (115) interlaced images corresponding with the array of lenticules.

There are provided volume holograms and combinations of lenticular lenses and holograms in particular for security applications. In embodiments, a volume hologram comprises a holographic medium (102) including a first optical interference structure which, upon illumination, replays a first image (110); wherein the first image includes a lenticular lens layer (111) including an array of lenticules and a lenticular image layer (113) including first (114) and second (115) interlaced images corresponding with the array of lenticules.

Embodiments for rendering holographic content by one or more processors are described. A security level associated with holographic content is determined. A security clearance associated with a viewer within a proximity of a holographic display is determined. The holographic content is caused to be rendered in a first mode or a second mode by the holographic display based on the determined security level associated with the holographic content and the determined security clearance associated with the viewer.

Provided are techniques for continuous authentication for a real time hologram. A request and a hologram are received, where the hologram is embedded with a first key phrase in accordance with a first sequence, and where the first sequence indicates which portions of the first key phrase are embedded in specific locations of the hologram. A first seed and a second seed are retrieved. A second key phrase is generated using the first seed. A second sequence is generated using the second seed. It is determined whether portions of the second key phrase are embedded in specific locations of the hologram in accordance with the second sequence. In response to determining that the portions of the second key phrase are embedded in specific locations of the hologram in accordance with the second sequence, the hologram is displayed, and the request is processed. Otherwise, the request is rejected.

Embodiments for rendering holographic content by one or more processors are described. A security level associated with holographic content is determined. A security clearance associated with a viewer within a proximity of a holographic display is determined. The holographic content is caused to be rendered in a first mode or a second mode by the holographic display based on the determined security level associated with the holographic content and the determined security clearance associated with the viewer.

The invention optical device comprising a self-processing photopolymer material configured to produce a variable two- or three- dimensional diffraction pattern when said material is illuminated by a light source. The invention provides a new material science and process technology which produces a serialisable anti-counterfeit optical device, based on a self-processing photopolymer.

Cryptographic techniques for encrypting images, and decrypting and reconstructing images, are provided to facilitate preventing unauthorized access to images. A holographic cryptographic component (HCC) generates complex holograms of multi-dimensional source images of a multi-dimensional object scene. The HCC generates phase holograms, based on the complex holograms, using a stochastic hologram generation process, and encrypts the phase holograms to generate encrypted holograms based on a random phase mask, which can be the private encryption key. At the decoding end, an HCC overlays a conjugate phase mask on the encrypted holograms to decrypt them, wherein the decrypted holograms are illuminated with a coherent light source to generate holographic images that reconstruct the source images. The source images are 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.

Cryptographic techniques for encrypting images, and decrypting and reconstructing images, are provided to facilitate preventing unauthorized access to images. A holographic cryptographic component (HCC) generates complex holograms of multi-dimensional source images of a multi-dimensional object scene. The HCC generates phase holograms, based on the complex holograms, using a stochastic hologram generation process, and encrypts the phase holograms to generate encrypted holograms based on a random phase mask, which can be the private encryption key. At the decoding end, an HCC overlays a conjugate phase mask on the encrypted holograms to decrypt them, wherein the decrypted holograms are illuminated with a coherent light source to generate holographic images that reconstruct the source images. The source images are 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.