This patent document discloses physical documents including metameric ink pairs. One claim recites a document comprising: a first surface; a second surface, in which the first surface comprises a first set of print structures and a second set of print structures, in which the first set of print structures and the second set of print structures collective convey an encoded signal discernable from optical scan data representing at least a first portion of the first surface, in which the first set of print structures is provided on the first surface with a first ink and the second set of print structures is provided on the first surface with a second, different ink, and in which the first ink and the second, different ink comprise a metameric pair. Of course, other claims and combinations are described as well.

This patent document discloses physical documents including metameric ink pairs. One claim recites a document comprising: a first surface; a second surface, in which the first surface comprises a first set of print structures and a second set of print structures, in which the first set of print structures and the second set of print structures collective convey an encoded signal discernable from optical scan data representing at least a first portion of the first surface, in which the first set of print structures is provided on the first surface with a first ink and the second set of print structures is provided on the first surface with a second, different ink, and in which the first ink and the second, different ink comprise a metameric pair. Of course, other claims and combinations are described as well.

A banknote includes a security element with a processor and a memory. A private cryptographic key of an asymmetric key pair of the banknote is stored in a protected memory area of the memory. The asymmetric key pair is assigned to a banknote-specific blockchain address in a blockchain. A payment method executed with the banknote includes receiving a payment request for a payment with the banknote in the form of a transaction of an amount to be paid from the blockchain address of the banknote to a blockchain address of a payee, signing a transaction approval with the private cryptographic key of the banknote, and sending the signed transaction approval.

A banknote includes a security element with a processor and a memory. A private cryptographic key of an asymmetric key pair of the banknote is stored in a protected memory area of the memory. The asymmetric key pair is assigned to a banknote-specific blockchain address in a blockchain. A payment method executed with the banknote includes receiving a payment request for a payment with the banknote in the form of a transaction of an amount to be paid from the blockchain address of the banknote to a blockchain address of a payee, signing a transaction approval with the private cryptographic key of the banknote, and sending the signed transaction approval.

A user device may cause light to be emitted at a security article by one or more light emission devices of the user device. The user device may obtain from a first set of one or more optical sensor devices of the user device first sensor data associated with the security article, and may obtain from a second set of one or more optical sensor devices of the user device second sensor data associated with the security article. The user device may determine, based on the first sensor data and the second sensor data, one or more characteristics of a security feature of the security article. The user device may determine, based on the one or more characteristics of the security feature, whether the security article is authentic. The user device may cause, based on determining whether the security article is authentic, one or more actions to be performed.

The Counter-Terrorism Currency System is a type of currency designed to combat financial fraud and Terrorism. The Counter-Terrorism Currency System is also known as the CT Currency System

The CT Currency will be in two forms.

The CT Paper Currency and the CT Digital Currency

The CT paper Currency will be paper money with an embedded CT Code, which stands for “Counter-Terrorism Code. “This CT code allows users to scan the CT paper currency with their smartphone through the CT Currency Mobile App.

Both sides of the CT paper Currency will be embedded with the CT code. one side is for transactions, and the other is for the bank used only. The bank used the only section used by the bank whenever the paper gets lost to find the rightful owner.

The Counter-Terrorism Currency System is a type of currency designed to combat financial fraud and Terrorism. The Counter-Terrorism Currency System is also known as the CT Currency System

The CT Currency will be in two forms.

The CT Paper Currency and the CT Digital Currency

The CT paper Currency will be paper money with an embedded CT Code, which stands for “Counter-Terrorism Code. “This CT code allows users to scan the CT paper currency with their smartphone through the CT Currency Mobile App.

Both sides of the CT paper Currency will be embedded with the CT code. one side is for transactions, and the other is for the bank used only. The bank used the only section used by the bank whenever the paper gets lost to find the rightful owner.

A method is provided for detecting a security thread in a value document, in which magnetic data are employed for sites on the value document. The magnetic data represents a magnetic property of the value document at the site, check sites on the value document are determined employing the sites, and from the check sites, a straight line is specified, along or on which at least some of the check sites lie and which represents a location of the security thread.

A method is provided for detecting a security thread in a value document, in which magnetic data are employed for sites on the value document. The magnetic data represents a magnetic property of the value document at the site, check sites on the value document are determined employing the sites, and from the check sites, a straight line is specified, along or on which at least some of the check sites lie and which represents a location of the security thread.

Machine-executable instructions arranged to be executed by a processor of an authenticating apparatus, and the instructions configured to read a machine-readable security feature provided on or which is part of the optical authentication structure, and to thereby cause a display of the apparatus to show at least part of the optical authentication structure and augmented reality imagery, which augmented reality imagery at least in part allows the optical authentication structure to be authenticated.