Glossary

The science and technology of precisely manipulating the structure of matter at the atomic and molecular level. In the authentication sector, nanotechnology is used to explore and develop unique optical phenomena for use in new material and security features.

In general, refers to the central banks of different countries that are part of a currency union.

A foundational identification system that provides national IDs – often an identity document – and potentially other credentials. In many countries, a primary function of national ID systems has been to establish and provide recognition and proof of nationality and/or residency status.

A method of wireless data transfer between two electronic devices over a distance of 4cm or less.

The part of the electromagnetic spectrum between 780nm and 2500nm, near-infrared is the region closest in wavelength to the red light detectable by the human eye.

When the nominal interest rate drops below 0% for a specific economic zone. This effectively means that banks and other financial firms have to pay to keep their excess reserves stored at the central bank, rather than receiving positive interest income. This is hard to enforce while people have the option to hold funds in other assets, particularly physical cash.

The value or units of banknotes (or coins) issued by a central bank over a period, minus the equivalent withdrawn from circulation during the same period. A positive net issuance expresses an increase in circulation during the period.

Computers in a cryptocurrency network.

The value stated on a coin or banknote, ie. face value.

A unit of data stored on a blockchain digital ledger that certifies a digital asset to be unique and therefore not interchangeable Used to represent ownership of real-world unique items like art, video clips and music – unlike money or bitcoin, which are fungible.

The study of paper money or banknotes.

System used in some countries in which the central bank delegates the safekeeping and distribution of banknotes to private entities and offers some sort of financial compensation to incentivise the system. See also Balance sheet relief mechanism.

Numbering enables a banknote to be differentiated from another banknote of the same denomination. If two banknotes have the same numbering it is proof that one of them is false. Numbering is usually on one side of the note, but can be on the front or the back.

The science, study or collecting of coins, medals, paper money and related objects. In the scope of banking services, the numismatic service deals with the sale of legal, former or rare banknotes and coins to customers with collecting interests.

A price that is given to a numismatic object. It may deviate from the face value as a result of various factors: the degree of rarity, the state of the object’s preservation, the artistic relevance and the historical significance.

A collector or knowledgeable person in the field of numismatics.

A wave reflected from an object and incident on a usually photosensitive material. Also refers to the beam that is transmitted and diffracted by a holographic plate (H1) which becomes the ‘object’ from which a copy (H2) is made. See also Reference beam.

Light from the side, falling at a shallow angle, and revealing the surface structure of an object through contrasts of light and shade. Oblique light is used especially to inspect embossing stamps, intaglio printing, latent images and mechanical erasures.

With a banknote, this is the main side that portrays the most representative motif, often the effigy of a ruling monarch or state symbol. With a coin, it is also the main side or face where a state symbol or portrait of the monarch and name of the country usually appear. The front side of a coin is commonly called ‘heads’ in coin tossing, while the other side is called ‘tails’.

The off-axis method is an origination technique where a laser beam is split into two beams: an object and a reference beam. The object beam illuminates the object/artwork and is scattered onto a photoresist. The reference beam is directed onto the photoresist from the same side but at a different angle (off-axis). The two beams meet and overlap at the photoresist, generating an interference pattern which, in essence, provides a three-dimensional holographic record of the object.

An indirect printing process whereby ink is spread on a metal plate with etched images, then transferred to an intermediary surface such as a rubber blanket, and finally applied to the substrate by pressing that substrate against the intermediary surface. With wet offset, the printing plate must be moistened with water before it is inked, whereas dry offset printing does not use water. Offset is often used in long secure document print runs and is the most common printing method for tax stamps.

A method for identifying an unknown individual, via biometric data such as a photo of their face or fingerprints, which is compared to a larger database to uncover a potential match. 

The optical property of a substrate that prevents transmission of light.

The reading and recognition of characters using an optical device.

Overt and semicovert security features with dynamic characteristics that change according to the viewing angle – eg. from one colour to another, or from one image to another.

A popular type of secure printing ink that contains microscopic pigments acting as interference filters, resulting in large colour shifts determined by the angle of lighting or viewing.

Process to check security features visible with simple smartphone cameras, such as diffractive motion effects based on the viewing angle.

Allows static controls using cameras at multiple wavelengths (visible and infrared light).

The process which transforms an initial design of a banknote or security document into an industrial product ready for printing.

A single-run multicolour printing method invented by Ivan Orlov in 1890 in Russia. Consists of creating separate ink layers on colour-separated plates and transferring the inks to a common plate and then to the receiving surface.

Tobacco products other than cigarettes, such as cigars and pipe tobacco.

Security features such as holograms that are apparent to the human senses – especially those of sight and touch – without the need for additional readers and instruments. Such features are designed to enable all stakeholders, including the public, to identify if something is genuine or not.

Name of a widely used colour matching system in graphic design, whereby each colour is coded with a reference number.

The most widely used banknote substrate throughout history, usually made from cotton, with short fibres that give a banknote special characteristics of touch, sound and firmness. It can also include other fibres of different origins.

The phenomenon in an image which allows depth to be judged from the movement of near image elements relative to more distant ones. Traditional embossed holograms only display parallax from side to side, but the lack of vertical parallax is rarely noticed. Ortho-parallax is the term for when the movement of the elements is in a counterintuitive direction (ie. 90°) to the angle of view.

A security feature that requires an action such as scanning or photocopying to become visible. See also Active security feature.

This is the main document certifying a person’s identity and allowing them to cross a border. A passport is issued to all individuals who are citizens or permanent residents of a particular country. It consists of a small book with a hard or a soft cover. It contains the holder’s personal identifying information, security features, information about the issuing country and issuing authority, and blank pages for visas and other marks.

In computing and telecommunications, the payload is the part of transmitted data that is the actual intended message.

Documents that can be used legally to effect payment in commercial banks in book money or currency. For example, cheques, bills of exchange, promissory notes.

A payment platform or network that moves money from payer to payee. Credit card rails are the credit card payment system.

Traditionally, PSPs have provided shops with online services for accepting electronic payments by a variety of payment methods including credit card, bank-based payments such as direct debit, bank transfer, and real-time bank transfer based on online banking. Typically, these are a software-as-a-service model and form a single payment gateway for clients (merchants) to multiple payment methods. For central bank digital currencies, PSPs are likely to facilitate the acceptance and use of CBDCs for payments.

Visibly similar to iridescence but with a slightly ‘milky’ appearance at certain viewing angles.

Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the application. They are said to form a peer-to-peer network of nodes.

An additional blockchain security system that maintains an access control layer to allow certain actions to be performed only by certain identifiable participants.

In the context of ID, personalisation refers to the combination of biographical data, variable text and signature that are added to a document to render it unique and link it to the document holder.

The fraudulent practice of sending emails or other messages purporting to be from reputable companies in order to induce individuals to reveal personal information, such as passwords and credit card numbers.

A type of fluorescence that continues for a period of time after the stimulus that produced the emission has stopped.

A light-induced reversible colour change which in its most familiar form involves an ultraviolet-induced transformation from colourless to coloured. Sunglasses that darken in the sunlight and revert to near colourless in subdued light constitute the most widely known application of photochromism. However, there are a diverse range of other applications and potential applications that include fuel markers, security inks and electronic nanotechnology.

Luminescence produced by exposure to ultraviolet light.

Holograms produced from materials that polymerise (combine to form a polymer) under the action of light energy and thus change their refractive index. Used to record volume reflection holograms (see Volume hologram).