In one embodiment, a printed security mark comprises a random arrangement of printed LEDs and a wavelength conversion layer. During fabrication of the mark, the LEDs are energized, and the resulting dot pattern is converted into a unique digital first code and stored in a database. The emitted spectrum vs. intensity and persistence of the wavelength conversion layer is also encoded in the first code. The mark may be on a credit card, casino chip, banknote, passport, etc. to be authenticated. For authenticating the mark, the LEDs are energized and the dot pattern, spectrum vs. intensity, and persistence are converted into a code and compared to the first code stored in the database. If there is a match, the mark is authenticated.

Encrypted markers that are not readily detectable can be revealed by treatment with a specific reagent used as a developer to reveal a readily detectable physical property of the marker, such as a characteristic fluorescence emission after excitation with a particular excitation wavelength, or to reveal a visible color. The encrypted marker can be developed in situ, or a sample can be removed by brushing, scraping, swabbing or scratching the marked object or item and developing the encrypted marker or a sample thereof with the appropriate developer to reveal an overt marker or optical signal. The encrypted marker may include a DNA taggant.

An identification method for identifying a target to be measured includes accepting, from an input section, an information representing a condition for acquiring spectral information specific to a target to be measured, capturing, by a spectrometry camera, an image of the target, acquiring the spectral information specific to the target based on the captured image, and identifying the target based on (i) the spectral information and (ii) a database, stored in a memory, containing a plurality of pieces of spectral information corresponding to a plurality of objects. Acquiring the spectral information includes preferentially acquiring the spectral information specific to the target in a specific wavelength region where the target is identifiable.

In order to perform high-accuracy authentication of a forgery prevention medium having a forgery prevention structure, a forgery prevention structure provided in or on a medium for performing authentication of the medium includes: an anisotropic resonator that resonates in response to being irradiated with a first terahertz electromagnetic wave at a first frequency, a transmissivity of the first terahertz electromagnetic wave changes with a polarization direction of the first terahertz electromagnetic wave, and an isotropic resonator that resonates in response to be irradiated with a second terahertz electromagnetic wave at a second frequency, a transmissivity of the second terahertz electromagnetic wave does not change with a polarization direction of the second terahertz electromagnetic wave.

A system for computerized authentication of a laminated object, the system comprising a digital medium storing a digital image of at least a portion of the laminated object in a computer-implemented memory; a shininess analyzer operative, using a processor, to generate shininess data quantifying shininess of the digital image; and a parameterized computerized authentication sub-system operative to differentially perform at least one laminated object authentication operation based on the shininess data.

An optical storage phosphor, a method for checking an authenticity feature, and an apparatus for carrying out a method, relate to an authenticity feature and to a value document. An inorganic optical storage phosphor is provided having a garnet structure and predetermined composition.

A method of verifying an authenticity of a printed item includes: photographing the printed item to obtain a photographic image of the printed item, retrieving reference data of the printed item, the reference data including a reference image of the printed item, determining a test noise parameter from the photographic image of the printed item, determining a reference noise parameter from the reference image, comparing the test noise parameter of the photographic image of the printed item to the reference noise parameter of the reference image, and determining an authenticity of the printed item from a result of the comparing. The determining the authenticity of the printed item from the result of the comparing may include establishing from the reference noise parameter of the reference image and the test noise parameter of the printed item.

An imaging system (200) for imaging and generating a measure of authenticity of an object (10) comprises a dispersive imaging arrangement (30) and an image sensor arrangement (60). They are positioned so that, when electromagnetic radiation (20) from the object (10) illuminates the dispersive imaging arrangement (30), the radiation splits out in different directions into at least a non-dispersed part (40) and a dispersed part (50), and those are imaged by the image sensor arrangement (60). The imaging system (200) is configured to then generate a measure of authenticity of the object (10) depending at least on a relation between the imaged dispersed part, the imaged non-dispersed part, and reference spectral information. The invention also relates to imaging methods, computer programs, computer program products, and storage mediums.

The present disclosure relates to an encoding method and a decoding method using a chiral metal nanostructure. The encoding method according to an aspect of the present disclosure includes preparing a plurality of metal nanostructures having a chiral structure; obtaining the optical data of the plurality of metal nanostructures, and preparing a security medium including the plurality of metal.

A method and apparatus for determining authenticity of objects using synchronous fluorescence spectroscopy (SFS). The fluorescent security feature of a flat object Q is identified under illumination with ultraviolet light. Then the security feature is illuminated by a beam of light at continuously varied excitation wavelength, while the intensity of emitted light (fluorescence) is recorded at the continuously varied, yet different emission wavelength. The difference between the wavelengths of emission and excitation is held constant, and the spectrum SFS(Q) is obtained. The same procedure is conducted with a known authentic (A) object, resulting in its synchronous fluorescence spectrum SFS(A). A comparison of SFS(Q) and SFS(A) is conducted. If SFS(Q) and SFS(A) are the same, the Q object is concluded to be authentic.