Glossary
705 termsWelcome to your glossary of over 700 terms and definitions related to sectors with security, authentication, and trust at their core.
While the emphasis of the glossary is on terms relating to security technologies and systems, it also extends to other terms commonly encountered in these different sectors. Is there a term missing that you need a definition for? Don't hesitate to let us know at [email protected].
Interoperability
The ability of different information systems, devices and applications to access, exchange, integrate and cooperatively use data in a coordinated manner, within and across organisational, regional and national boundaries.
Interpol
Name of the International Criminal Police Organisation, dating back to 1923. Its activity extends to all crimes of common law and especially those related to drug and gold trafficking, counterfeiting of money and capturing criminals harbouring in a foreign country. Police forces from most countries in the world take part in this organisation.
Iridescence
The ability of some materials to create rainbow effects when they reflect white light. Pearls, oil films on water and bubbles all show iridescence. The effect can be created with foils, ink, and laminates to create optically variable devices.
Iridescent ink
An ink containing (normally) tiny flakes of a shiny silicate mineral (mica) that interferes with incoming light to create a pearl effect on the finished document. Iridescent inks are sometimes used as low-grade security features. They are not the same as colour-shifting inks.
ISO 12931:2012
An ISO guidance standard for performance criteria for authentication solutions used to combat counterfeiting of material goods. This standard was revised under a new number: ISO 22383:2020.
ISO 14298:2021
An ISO compliance standard specifying requirements for a security printing management system for security printers. The certifying organisation behind 14298 is Intergraf.
ISO 22376:2023
An ISO standard for the specification and usage of visible digital seal (VDS) data format for authentication, verification and acquisition of data carried by a document or object.
ISO 22381:2018
An ISO guidance standard for establishing interoperability among object identification systems to deter counterfeiting and illicit trade.
ISO 22382:2018
An ISO guidance standard for the content, security, issuance and examination of excise tax stamps.
ISO 22383:2020
An ISO guidance standard for the selection and performance evaluation of authentication solutions for material goods.
ISO 22385:2023
An ISO guidance standard for establishing a framework for trust and interoperability.
ISO 22388:2023
An ISO guidance standard for securing physical documents.
ISO/CD 22373
An ISO guidance standard, under development, for establishing trustworthy supply chains for material goods.
ISO/IEC 15459-3:2014
An ISO/IEC (International Electrotechnical Commission) standard specifying common rules for unique identification required to ensure full compatibility across different identities.
ISO/IEC 20248:2022
An ISO/IEC (International Electrotechnical Commission) standard specifying a method whereby data stored within a barcode or RFID tag are structured, encoded and digitally signed.
Isotope
Atoms of the same element with the same number of protons (atomic number) but a different number of neutrons.
Isotopic tags
A forensic marker technology that involves adding isotopic variants of one or more components of a formulation or packaging to allow the identification of genuine products.
Issuing authority
The entity authorised to issue money of legal tender in a country. Generally, the expression is synonymous with a central bank or monetary authority. Also refers to government authorities issuing ID documents, tax stamps and other secure documents.
Keys – private and public
akaA system of encryption whereby a ‘key’ is required to decode a message. The key is usually a handheld device which renders meaningful that which was previously unintelligible. Public keys may be disseminated widely, whereas private keys are restricted to certain individuals, thereby limiting access to the encrypted information. See also Public key infrastructure.
Kinetic
An adjective whose roots in the Greek word ‘kinesis’ indicate motion. A holographic image which displays movement of form or colour is said to be kinetic. Often, such images are patterns rather than objects. The patterns can be made up of fine lines or graphic elements and appear to scintillate when moved.
Kiss cut
akaA tamper-resistant feature employing a die-cutting process whereby adhesive-backed foils or papers are cut through, but the laminated backing paper is not.
Laser
An acronym of ‘light amplification by stimulated emission of radiation’, a device that produces coherent light by stimulated emission of radiation.
Laser printing
An electrostatic digital printing process that produces text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a ‘drum’, which defines a differentially charged image. Laser colour digital copiers use this printing technique. It is a technique used in counterfeiting banknotes and other security documents.
Latent image
An image formed by parallel straight relief strokes perpendicular to background strokes. The image is almost invisible in incidental white light at a right angle. It is visualised as an achromatic image in sliding white light at an acute angle of observation due to the shadow cast by the relief strokes. The background and image are applied by means of intaglio and have the same colour and stroke density.
Latent multicolour image
A latent image formed by multicolour relief strokes. A latent multicolour image is slightly visible in white light. It is visualised as a chromatic image under oblique light. Every chromatic element of the image changes colour when rotating the document around the vertical axe without changing the angle of observation. Background strokes are applied by offset and relief lines by intaglio.
Latent scrambled image
A latent image that has been fragmented and encoded according to a special algorithm. The image is visualised via a lenticular decoding device.
Lenticular lens
An array of lenses, designed so that when viewed from slightly different angles reveal different parts of an image. The most common example are the lenses used in lenticular printing to give an illusion of depth, or to make images that appear to change or move according to the viewing angle.
Lenticular printng
A multistep process consisting of creating a lenticular image from at least two existing images, and combining it with a lenticular lens. This process can be used to create various frames of animation (for a motion effect), offsetting the various layers at different increments (for a 3D effect), or simply to show a set of alternate images which may appear to transform into each other.
Letterpress printing
A relief printing process by which many copies are produced by repeated direct impression of an inked, raised surface against sheets or a continuous roll of paper. Letterpress printing remained the primary means of printing and distributing information until the 20th century, when offset printing was developed, which largely supplanted the role of letterpress in printing books and newspapers.
Level 1, 2, 3 and 4 security features
A commonly used means of grading security features created by the European Central Bank and adopted for use across the banknote industry. Level 1 refers to features that can be verified by the public, untrained examiners or specialist examiners with the naked eye. Level 2 refers to semicovert features that require some form of reading device or tool to be authenticated. They are typically deployed for use by retailers, cashiers and inspectors but are also detected by sensors in machines (the ECB defines Level 2a, 2b and 2c). Level 3 refers to covert features, generally rare chemicals or compounds that can only be identified by sensors in high speed processing machine verification used in cash centres. Level 4 authentication uses forensic examination to verify banknotes and is used solely by central banks/police.
Line width modulation
Manipulating the width, length and height of line structures to create image and text effects. Using a higher resolution for the output results in effects not possible with commercially available software.
Liquid crystal
Chemicals that have properties between those of conventional liquids and solid crystals. Orientation of the crystal-like structure of the chemicals results in optically variable effects. Cholesteric liquid crystals have two refractive indices, a property known as birefringence (the ability to rotate the polarisation of incoming light and reflect circularly polarised light either clockwise or anticlockwise). Liquid crystal technology is used for security features that are validated with a polarisng filter.
Luminescence
A collective term for the effects of colour change or other visible characteristics under different sources of illumination.
Machine learning
An umbrella term for solving problems for which development of algorithms by human programmers would be cost-prohibitive, and instead the problems are solved by helping machines ‘discover’ their ‘own’ algorithms, without needing to be explicitly told what to do by any human-developed algorithms. While artificial intelligence encompasses the idea of a machine that can mimic human intelligence, machine learning does not. Machine learning aims to teach a machine how to perform a specific task and provide accurate results by identifying patterns.
Machine-readable
A security feature requiring an instrument to verify its presence or data content.
Machine vision
The ability of a computer to see. The technology and methods used to provide imaging-based automatic inspection and analysis for such applications as automatic inspection, process control, and robot guidance, usually in industry.
Magnetic ink
An ink containing ferromagnetic components that have a specific reaction to the external magnetic field. Text or symbols applied by this ink can be identified by special magnetic sensors or visualised by magneto-optic converters. The ink can be applied on security threads and fibres,and used for printing images, serial numbers and barcodes.
Mass spectrometry
An analytical technique to quantify known materials and identify unknown compounds within a sample and elucidate the structure and chemical properties of different molecules.
Master case
A shipping unit of tobacco products – usually comprising 25 or 50 cartons.
Matrix code
A 2D barcode (eg. datamatrix, QR code, dotcode), typically square-shaped, capable of representing more data per unit area than a linear barcode.
Megapixel
One million pixels. The term is used not only for the number of pixels in an image but also to express the number of image sensor elements of digital cameras or the number of display elements of digital displays.
Metallic ink
Printing ink containing metallic components that provide a metallic finish to the applied substrate.
Metallisation
The coating of films or surfaces with a very thin layer of metal using a metal deposition technique. Metallisation is what gives holograms their silver or similar metallic appearance.
Metameric ink pair
A pair of similarly shaded inks, the colour and contrast of which appear virtually identical in normal light, but which have different spectral responses so that, when viewed in another light (such as infrared), one ink displays different effects or colours to the other. In the case of IR pairs, one ink absorbs IR and the other reflects it, and only the IR-reflecting part can be seen through a filter.
Metasurface – electromagnetic
Thin 2D metamaterial layers that allow or inhibit the propagation of electromagnetic waves in desired directions.
Microchip – contact
An integrated circuit embedded into a recessed area on the surface of, for example, an ID card or passport to store and process personal data. A secure document containing a contact microchip must be inserted into a card reader so that the chip can make contact with electrical terminals and allow information to be read.
Microchip – contactless
An integrated circuit embedded under the surface of, for example, an ID card or passport to store and process personal data. The microchip is connected to an aerial (electromagnetic loop antenna) which allows communication with a card reader via electromagnetic waves (RFID). To supply the microchip with energy and to start communication, the card must be in close proximity to the reader.
Microlens
Small lenses, typically only a few microns in size.
Micromirror
Tiny microscopic mirrors created using origination techniques similar to those used for diffractive OVDs (optically variable devices). Micromirrors reflect light in a specific manner defined by the size and orientation of the mirrors.
Micron
(µm) akaA unit of measurement commonly used in authentication when referring to the thickness or gauge of physical substrates and features. One micron is equal to one millionth (10-6) of a metre.