Storage media are provided. A substrate has an array of addressable locations thereon, each addressable location adapted to be physically associated with a collection of molecules, each collection comprising at least a first subcollection of molecules and a second subcollection of molecules. The molecules in the collection are selected from a set of unambiguously identifiable molecules, the set comprising at least a first subset of molecules and a second subset of molecules. Each molecule in the first subset is identifiable by a first physical property, and each molecule in the second subset is identifiable by a second physical property, different from the first physical property. Each molecule in the set is uniquely associated with a predetermined position in a numerical value, wherein the presence of the molecule in the collection indicates a predetermined digit at the associated position and the absence of said molecule in the collection indicates a zero at said associated position.

A color image display device comprising arrays of structural color pixels, where said structural color pixels may be formed on a single substrate layer or multiple substrate layers and are patterned by selective material deposition to display a color image in accordance with input color images or patterns. The structural color pixels comprise a plurality of microstructures and/or nanostructures, including without limitation, diffraction gratings, sub-wavelength structures, to display colors in red, green, blue in RGB color space or cyan, magenta, yellow in CMY color space. Examples include methods of activating and/or deactivating structural pixels using selective material deposition onto at least one layer of the color display device to form a color image. Further examples include product labels, authentication devices and security documents carrying customized or personalized information and methods for their manufacture.

An optically variable device uses a data storage layer with a nano-optical bit system to store data. The optically variable device encodes the data using spectral signatures (such as colors) as variables. In some embodiments, the optically variable device uses angle multiplexing to store machine-readable data and an image. The optically variable device can be used as a secure data storage medium for a large volume of data. The storage capacity can be increased by increasing the number of color variables and by introducing additional variables such as intensity and polarization.

In some embodiments, an apparatus includes a tag that may include an encapsulant and a plurality of three-dimensional objects randomly oriented within the encapsulant. Each three-dimensional object may include a plurality of characteristics defining at least one statistically unique signature. At least one of the characteristics may be dependent on the orientation of the object. In some instances, the plurality of three-dimensional objects may also be randomly distributed within the encapsulant, and at least one of the characteristics defining at least one statistically unique signature may be dependent on the distribution of the objects.

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.

In one embodiment, a printed LED area comprises a random arrangement of printed LEDs and a wavelength conversion layer. The LED area is embedded in an object to be authenticated, such as a credit card or a casino chip. The object may include a light guide for enabling the generated light to be emitted from any portion of the object. In one embodiment, when the LEDs are energized during authentication of the object, the existence of light emitted by the object is sufficient authentication and/or provides feedback to the user that the object is being detected. For added security, the emitted spectrum vs. intensity and persistence of the wavelength conversion layer is detected and encoded in a first code, then compared to valid codes stored in the database. If there is a match, the object is authenticated.

An optically variable device uses a data storage layer with a nano-optical bit system to store data. The optically variable device encodes the data using spectral signatures (such as colors) as variables. In some embodiments, the optically variable device uses angle multiplexing to store machine-readable data and an image. The optically variable device can be used as a secure data storage medium for a large volume of data. The storage capacity can be increased by increasing the number of color variables and by introducing additional variables such as intensity and polarization.

A method and an apparatus (10) for generating a three-dimensional work piece containing an information code are provided. The method comprises the steps of applying a raw material powder (18) onto a carrier (14) by means of a powder application device (16), irradiating electromagnetic or particle radiation (22) onto the raw material powder (18) applied onto the carrier (14) by means of an irradiation device (20), and controlling the operation of the powder application device (16) and the irradiation device (20) so as to generate an information code pattern (36) on or in the work piece (12), wherein the information code pattern (36) is defined by the microstructure (34) of the work piece (12).

In some embodiments, an apparatus includes a tag that may include an encapsulant and a plurality of three-dimensional objects randomly oriented within the encapsulant. Each three-dimensional object may include a plurality of characteristics defining at least one statistically unique signature. At least one of the characteristics may be dependent on the orientation of the object. In some instances, the plurality of three-dimensional objects may also be randomly distributed within the encapsulant, and at least one of the characteristics defining at least one statistically unique signature may be dependent on the distribution of the objects.

An object marking including a first security element and at least a second security element, wherein each security element is associated with a set of data segments and each security element exhibits depending on the capturing conditions, in particular the viewing angle and/or the direction of illumination, a code segment which is an optoelectronically readable representation of one of the data segments of the set associated with the respective security element, wherein different distinct data segments are represented by different code segments and that the set associated with the first security element and the set associated with the second security element differ in at least one data segment; method for producing and method for authenticating the same.