A method of authenticating an object (12) includes applying indicia (14) to the object, wherein the indicia includes at least two different types of particles which fluoresce upon exposure to light (15) and which have different decay rates. The indicia is exposed to light from a lamp (32) causing the plurality of particles to fluoresce. At least a first image of the indicia is captured with a sensor (22) at a first time and a second image of the indicia at a second time different from the first time. The images are analyzed to determine decay rates of the at least two types of particles and object is authenticated if the decay rates match stored information.

A method of authenticating an object (12) includes applying indicia (14) to the object, wherein the indicia includes at least two different types of particles which fluoresce upon exposure to light (15) and which have different decay rates. The indicia is exposed to light from a lamp (32) causing the plurality of particles to fluoresce. At least a first image of the indicia is captured with a sensor (22) at a first time and a second image of the indicia at a second time different from the first time. The images are analyzed to determine decay rates of the at least two types of particles and object is authenticated if the decay rates match stored information.

A method of authentication using surface paper texture includes steps of capturing a topographic pattern image of a surface of a region of interest of the paper artifact and extracting a plurality of specific features from the captured topographic pattern image. The method further identifies the location of the specific features of the paper artifact from the captured topographic pattern image. A bit map of the identified location of the specific features is generated. Then, a reference image of a reference bit map printed on the region of interest of the paper artifact is captured. Finally, the method compares the generated bit map with the captured reference bit map to generate a score. The score of the comparison determines the level of authentication. The method provides an offline method of authentication.

A method of authentication using surface paper texture includes steps of capturing a topographic pattern image of a surface of a region of interest of the paper artifact and extracting a plurality of specific features from the captured topographic pattern image. The method further identifies the location of the specific features of the paper artifact from the captured topographic pattern image. A bit map of the identified location of the specific features is generated. Then, a reference image of a reference bit map printed on the region of interest of the paper artifact is captured. Finally, the method compares the generated bit map with the captured reference bit map to generate a score. The score of the comparison determines the level of authentication. The method provides an offline method of authentication.

Hydrogel microparticles spatially and spectrally encoded using upconverting phosphor nanoparticles are described for use in biochemical testing. In each microparticle, upconversion nanocrystals having spectrally distinguishable emission spectra are disposed in different partions of an encoding region of the microparticle.

The present application relates to an anti-counterfeiting object including a face with an optical identification marking which is readable by the eye and/or by a machine, and an authentication volume, the authentication volume extending from the face in the thickness (z) direction so as to be accessible from the face in order to be read by X-ray diffractometry (XRD). The authentication volume is a composite of a first material, referred to as the authentication material, and at least one second material, the authentication volume constituting a material volume of at least 5 mm.sup.3. The authentication material includes at least one amorphous phase, at least one crystalline phase and at least one complex metal phase. The second material is typically a polymer. The application may advantageously be implemented by 3D printing.

A system for verifying the authenticity of a printed mark includes an image acquisition device that acquires an image of a printed mark. In one implementation, the printed mark includes an identifier that identifies the group or class of an item to which the printed mark is to be (or has been) attached. The system may also include one or more processors that carry out actions such as receiving the image from the image acquisition device; analyzing the image to identify artifacts in the printed mark, retrieving a genuine mark signature from a data storage containing genuine mark signatures, comparing the identified artifacts with the genuine mark signature, and determining whether the unverified item is authentic based on the comparison.

An article and method of manufacturing an authenticatable finished fabric and article comprising the steps of: obtaining an original fabric article comprising authentic fiber, the original fabric article being possessed at some time by at least one person; breaking the original fabric article into authentic fiber components; blending the authentic fiber components with virgin fiber to make a authentic fiber blend; generating a authentic fiber blend yarn; weaving or knitting a finished fabric that is configured to form a binary code from a mixture of the authentic fiber blend yarn and a filling yarn; and creating a first level authentication and an second level authentication of the finished fabric with the first and second level authentication being non-interacting or independent.

An article and method of manufacturing an authenticatable finished fabric and article comprising the steps of: obtaining an original fabric article comprising authentic fiber, the original fabric article being possessed at some time by at least one person; breaking the original fabric article into authentic fiber components; blending the authentic fiber components with virgin fiber to make a authentic fiber blend; generating a authentic fiber blend yarn; weaving or knitting a finished fabric that is configured to form a binary code from a mixture of the authentic fiber blend yarn and a filling yarn; and creating a first level authentication and an second level authentication of the finished fabric with the first and second level authentication being non-interacting or independent.

A printing ink having a first fluorescent dye acting as donor and a second fluorescent dye acting as acceptor. The first fluorescent dye, upon excitation by electromagnetic radiation falling within an excitation wavelength range λ.sub.1a of the first fluorescent dye, is capable of emitting electromagnetic radiation in at least one first emission wavelength range λ.sub.1e, said first emission wavelength range λ.sub.1e of the first fluorescent dye overlapping with at least one excitation wavelength range λ.sub.2a of the second fluorescent dye, to thereby excite the second fluorescent dye to emit electromagnetic radiation in a second emission wavelength range λ.sub.2e.