Systems, devices, methods, and instructions for travel document validation, including receiving data for one or more travel documents, generating a set of features for artificial intelligence model training, validating, and testing, upon receiving data for a plurality of travel documents, data from a first subset of travel documents is used to train an artificial intelligence model, a second subset of travel documents is used to validate the artificial intelligence model, and a third subset of travel documents is used to test the artificial intelligence model.

A multipage security document has a first verification lens located in a see-through portion and corresponding to a first verification feature and a second verification lens collocated with the first verification lens as an adjacent layer to the first verification lens in the see-through portion and corresponding to a second verification feature. The multipage security document can contain a first sheet and a second sheet connected along one side to the first sheet such that the second sheet may be placed against the first sheet, the second sheet having a see-through portion. Other embodiments are disclosed.

Methods and systems disclosed herein may communicate information, such as alerts and notifications, to a cardholder via a color-changing transaction card. In particular, the cardholder may configure one or more thresholds that establish when a transaction card may change colors. For instance, a transaction card may change colors at, or while approaching, a first threshold. The transaction card may change colors at, or while approaching, a second threshold. When the cardholder's balance goes below the thresholds, the transaction card may revert back to the lower threshold color or the original color of the transaction card. Using the techniques described herein a financial institution may convey information to a cardholder in a way that does not require the cardholder to digitally engage with the financial institution.

Methods and systems disclosed herein may communicate information, such as alerts and notifications, to a cardholder via a color-changing transaction card. In particular, the cardholder may configure one or more thresholds that establish when a transaction card may change colors. For instance, a transaction card may change colors at, or while approaching, a first threshold. The transaction card may change colors at, or while approaching, a second threshold. When the cardholder's balance goes below the thresholds, the transaction card may revert back to the lower threshold color or the original color of the transaction card. Using the techniques described herein a financial institution may convey information to a cardholder in a way that does not require the cardholder to digitally engage with the financial institution.

The absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.

The absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.

A security marking has a physically unclonable function (PUF) wherein the PUF includes a disordered multilayer photonic crystal structure having an electromagnetic transmission and/or reflection spectrum and/or spectra upon receipt of electromagnetic radiation within a photonic bandgap region of the structure that is unique to the structure.

A security marking has a physically unclonable function (PUF) wherein the PUF includes a disordered multilayer photonic crystal structure having an electromagnetic transmission and/or reflection spectrum and/or spectra upon receipt of electromagnetic radiation within a photonic bandgap region of the structure that is unique to the structure.

A device for verifying a machine-readable security feature of a document of value, having: a transport device configured to transport the document on a transport plane, a radiation emitter that is arranged on a first flat side and emits radiation in the direction towards the first flat side, a sensor that is arranged on the first flat side and is configured to receive at least part of the luminescent radiation, a reflector arranged and configured on the second flat side-so as to at least partly reflect the luminescent radiation of the security feature of the document of value to the sensor, and an evaluation unit.

A device for verifying a machine-readable security feature of a document of value, having: a transport device configured to transport the document on a transport plane, a radiation emitter that is arranged on a first flat side and emits radiation in the direction towards the first flat side, a sensor that is arranged on the first flat side and is configured to receive at least part of the luminescent radiation, a reflector arranged and configured on the second flat side-so as to at least partly reflect the luminescent radiation of the security feature of the document of value to the sensor, and an evaluation unit.