Herein is described a scratch-off structure comprising the following layers in order: a substrate having a first layer showing information thereon, a second layer comprising a polymeric film and being substantially transparent; a third layer comprising a transparent electrostatic ink; a fourth layer, wherein the fourth layer is coloured. Methods for making scratch-off structures and collections of scratch-off structures are also described.

Manufacturing a counterfeit resistant document as a randomized assembly of material constituents with a large variety of electrical conductivity attributes, thereby achieving a unique set of physically measured properties of the document, so that a document verifier will be convinced of the authenticity of the document by comparing the results of real time measurements with measurements pre-recorded in a public ledger.

Manufacturing a counterfeit resistant document as a randomized assembly of material constituents with a large variety of electrical conductivity attributes, thereby achieving a unique set of physically measured properties of the document, so that a document verifier will be convinced of the authenticity of the document by comparing the results of real time measurements with measurements pre-recorded in a public ledger.

A security system for an article of manufacture includes one or more first planchettes and one or more second planchettes included in the article. The first planchettes luminesce under a first frequency of light and the second planchettes luminesce under a second frequency of light with at least one of three characteristics. First, the first frequency is different from the second frequency, the first planchettes do not luminesce under the second frequency of light, and the second planchettes do not luminesce under the first frequency of light. Second, the first planchettes luminesce at a first color under the first frequency of light and the second planchettes luminesce at a second color different from the first color under the second frequency of light. Third, the first planchettes reflect a first pattern under the first frequency of light and the second planchettes reflect a second pattern under the second frequency of light.

A security system for an article of manufacture includes one or more first planchettes and one or more second planchettes included in the article. The first planchettes luminesce under a first frequency of light and the second planchettes luminesce under a second frequency of light with at least one of three characteristics. First, the first frequency is different from the second frequency, the first planchettes do not luminesce under the second frequency of light, and the second planchettes do not luminesce under the first frequency of light. Second, the first planchettes luminesce at a first color under the first frequency of light and the second planchettes luminesce at a second color different from the first color under the second frequency of light. Third, the first planchettes reflect a first pattern under the first frequency of light and the second planchettes reflect a second pattern under the second frequency of light.

Aspects described herein may allow for a payment card assembly including a payment card having a first surface, an opposed second surface, and an aperture extending through the payment card from the first surface to the second surface. An insert may be removably received in the aperture. Each of a plurality of identification elements may be configured to be removably received in the aperture and have an identification characteristic different than an identification characteristic of each of the other identification elements.

Aspects described herein may allow for a payment card assembly including a payment card having a first surface, an opposed second surface, and an aperture extending through the payment card from the first surface to the second surface. An insert may be removably received in the aperture. Each of a plurality of identification elements may be configured to be removably received in the aperture and have an identification characteristic different than an identification characteristic of each of the other identification elements.

Data processing apparatus is provided comprising one or more processors. The data processing apparatus may be configured to perform a method of determining authentication data for authenticating an object comprising one or more identification elements which are detectable when electromagnetic radiation is incident thereon. The method may comprise obtaining image data relating to one or more of the identification element(s) of the object, processing the image data to determine outline data relating to outline(s) of one or more of the identification element(s) to which the image data relates and determining the authentication data from the outline data.

Data processing apparatus is provided comprising one or more processors. The data processing apparatus may be configured to perform a method of determining authentication data for authenticating an object comprising one or more identification elements which are detectable when electromagnetic radiation is incident thereon. The method may comprise obtaining image data relating to one or more of the identification element(s) of the object, processing the image data to determine outline data relating to outline(s) of one or more of the identification element(s) to which the image data relates and determining the authentication data from the outline data.

Aspects described herein may allow for a payment card assembly including a payment card having a first surface, an opposed second surface, and an aperture extending through the payment card from the first surface to the second surface. An insert may be removably received in the aperture. Each of a plurality of identification elements may be configured to be removably received in the aperture and have an identification characteristic different than an identification characteristic of each of the other identification elements.